Routing policies for graphical processing units

ABSTRACT

Discussed herein is a routing mechanism for graphical processing units (GPUs) that are hosted on several host machines in a cloud environment. For a packet transmitted by a GPU of a host machine and received by a network device, the network device determines an incoming port-link of the network device on which the packet was received. The network device obtains a flow information associated with the packet, and computes, based on the flow information, an outgoing port-link of the network device in accordance with a hashing algorithm. The hashing algorithm is configured to hash packets received on a particular incoming port-link of the network device to be transmitted on a same outgoing port-link of the network device. The network device forwards the packet on the outgoing port-link of the network device.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a non-provisional of and claims the benefit of thefiling date of U.S. Provisional Application No. 63/215,264, filed onJun. 25, 2021, the contents of which are incorporated herein byreference in its entirety for all purposes.

FIELD

The present disclosure relates to a framework and routing mechanisms forgraphical processing units (GPUs) that are hosted on several hostmachines in a cloud environment.

BACKGROUND

Organizations continue to move business applications and databases tothe cloud to reduce the cost of purchasing, updating, and maintainingon-premise hardware and software. High performance compute (HPC)applications consistently consume 100 percent of the available computepower to achieve a specific outcome or result. HPC applications requirededicated network performance, fast storage, high compute capabilities,and significant amounts of memory-resources that are in short supply inthe virtualized infrastructure that constitutes today's commodityclouds.

Cloud infrastructure service providers offer newer and faster CPUs andgraphical processing units (GPUs) to address the requirements of HPCapplications. Typically, a virtual topology is constructed in order toprovision the various GPUs that are hosted on the several host machinesto communicate with one another. In practice, a ring topology isutilized in order to connect the various GPUs. However, ring networksare invariably blocking in nature. As such, the performance of theoverall system is degraded. Embodiments discussed herein address theseand other issues related to connectivity of GPUs spanning across severalhost machines.

SUMMARY

The present disclosure relates generally to routing mechanisms forgraphical processing units (GPUs) that are hosted on several hostmachines in a cloud environment. Various embodiments are describedherein, including methods, systems, non-transitory computer-readablestorage media storing programs, code, or instructions executable by oneor more processors, and the like. These illustrative embodiments arementioned not to limit or define the disclosure, but to provide examplesto aid understanding thereof. Additional embodiments are discussed inthe detailed description section, and further description is providedtherein.

One embodiment of the present disclosure is directed to a methodcomprising: for a packet transmitted by a graphical processing unit(GPU) of a host machine and received by a network device, determining,by the network device, an incoming port-link of the network device onwhich the packet was received; identifying, by the network device, basedon a GPU routing policy, an outgoing port-link corresponding to theincoming port-link, wherein the GPU routing policy is preconfiguredprior to receiving the packet and establishes a mapping of each incomingport-link of the network device to a unique outgoing port-link of thenetwork device; and forwarding, by the network device, the packet on theoutgoing port-link of the network device.

An aspect of the present disclosure provides for a system comprising oneor more data processors, and a non-transitory computer readable storagemedium containing instructions which, when executed on the one or moredata processors, cause the one or more data processors to perform partor all of one or more methods disclosed herein.

Another aspect of the present disclosure provides for a computer-programproduct tangibly embodied in a non-transitory machine-readable storagemedium, including instructions configured to cause one or more dataprocessors to perform part or all of one or more methods disclosedherein.

The foregoing, together with other features and embodiments will becomemore apparent upon referring to the following specification, claims, andaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Features, embodiments, and advantages of the present disclosure arebetter understood when the following Detailed Description is read withreference to the accompanying drawings.

FIG. 1 is a high level diagram of a distributed environment showing avirtual or overlay cloud network hosted by a cloud service providerinfrastructure according to certain embodiments.

FIG. 2 depicts a simplified architectural diagram of the physicalcomponents in the physical network within CSPI according to certainembodiments.

FIG. 3 shows an example arrangement within CSPI where a host machine isconnected to multiple network virtualization devices (NVDs) according tocertain embodiments.

FIG. 4 depicts connectivity between a host machine and an NVD forproviding I/O virtualization for supporting multitenancy according tocertain embodiments.

FIG. 5 depicts a simplified block diagram of a physical network providedby a CSPI according to certain embodiments.

FIG. 6 depicts a simplified block diagram of a cloud infrastructureincorporating a CLOS network arrangement, according to certainembodiments.

FIG. 7 depicts an exemplary scenario depicting a flow collision in thecloud infrastructure of FIG. 6 , according to certain embodiments.

FIG. 8 depicts a policy based routing mechanism implemented in the cloudinfrastructure, according to certain embodiments.

FIG. 9 depicts a block diagram of a cloud infrastructure illustratingdifferent types of connections in the cloud infrastructure, according tocertain embodiments.

FIG. 10 illustrates an exemplary configuration of a rack included in thecloud infrastructure, according to certain embodiments.

FIG. 11A illustrates a flowchart depicting steps performed by a networkdevice in routing a packet, according to certain embodiments.

FIG. 11B illustrates another flowchart depicting steps performed by anetwork device in routing a packet, according to certain embodiments.

FIG. 12 is a block diagram illustrating one pattern for implementing acloud infrastructure as a service system, according to at least oneembodiment.

FIG. 13 is a block diagram illustrating another pattern for implementinga cloud infrastructure as a service system, according to at least oneembodiment.

FIG. 14 is a block diagram illustrating another pattern for implementinga cloud infrastructure as a service system, according to at least oneembodiment.

FIG. 15 is a block diagram illustrating another pattern for implementinga cloud infrastructure as a service system, according to at least oneembodiment.

FIG. 16 is a block diagram illustrating an example computer system,according to at least one embodiment.

DETAILED DESCRIPTION

In the following description, for the purposes of explanation, specificdetails are set forth in order to provide a thorough understanding ofcertain embodiments. However, it will be apparent that variousembodiments may be practiced without these specific details. The figuresand description are not intended to be restrictive. The word “exemplary”is used herein to mean “serving as an example, instance, orillustration.” Any embodiment or design described herein as “exemplary”is not necessarily to be construed as preferred or advantageous overother embodiments or designs.

Example Architecture of Cloud Infrastructure

The term cloud service is generally used to refer to a service that ismade available by a cloud services provider (CSP) to users or customerson demand (e.g., via a subscription model) using systems andinfrastructure (cloud infrastructure) provided by the CSP. Typically,the servers and systems that make up the CSP's infrastructure areseparate from the customer's own on-premise servers and systems.Customers can thus avail themselves of cloud services provided by theCSP without having to purchase separate hardware and software resourcesfor the services. Cloud services are designed to provide a subscribingcustomer easy, scalable access to applications and computing resourceswithout the customer having to invest in procuring the infrastructurethat is used for providing the services.

There are several cloud service providers that offer various types ofcloud services. There are various different types or models of cloudservices including Software-as-a-Service (SaaS), Platform-as-a-Service(PaaS), Infrastructure-as-a-Service (IaaS), and others.

A customer can subscribe to one or more cloud services provided by aCSP. The customer can be any entity such as an individual, anorganization, an enterprise, and the like. When a customer subscribes toor registers for a service provided by a CSP, a tenancy or an account iscreated for that customer. The customer can then, via this account,access the subscribed-to one or more cloud resources associated with theaccount.

As noted above, infrastructure as a service (IaaS) is one particulartype of cloud computing service. In an IaaS model, the CSP providesinfrastructure (referred to as cloud services provider infrastructure orCSPI) that can be used by customers to build their own customizablenetworks and deploy customer resources. The customer's resources andnetworks are thus hosted in a distributed environment by infrastructureprovided by a CSP. This is different from traditional computing, wherethe customer's resources and networks are hosted by infrastructureprovided by the customer.

The CSPI may comprise interconnected high-performance compute resourcesincluding various host machines, memory resources, and network resourcesthat form a physical network, which is also referred to as a substratenetwork or an underlay network. The resources in CSPI may be spreadacross one or more data centers that may be geographically spread acrossone or more geographical regions. Virtualization software may beexecuted by these physical resources to provide a virtualizeddistributed environment. The virtualization creates an overlay network(also known as a software-based network, a software-defined network, ora virtual network) over the physical network. The CSPI physical networkprovides the underlying basis for creating one or more overlay orvirtual networks on top of the physical network. The virtual or overlaynetworks can include one or more virtual cloud networks (VCNs). Thevirtual networks are implemented using software virtualizationtechnologies (e.g., hypervisors, functions performed by networkvirtualization devices (NVDs) (e.g., smartNICs), top-of-rack (TOR)switches, smart TORs that implement one or more functions performed byan NVD, and other mechanisms) to create layers of network abstractionthat can be run on top of the physical network. Virtual networks cantake on many forms, including peer-to-peer networks, IP networks, andothers. Virtual networks are typically either Layer-3 IP networks orLayer-2 VLANs. This method of virtual or overlay networking is oftenreferred to as virtual or overlay Layer-3 networking. Examples ofprotocols developed for virtual networks include IP-in-IP (or GenericRouting Encapsulation (GRE)), Virtual Extensible LAN (VXLAN—IETF RFC7348), Virtual Private Networks (VPNs) (e.g., MPLS Layer-3 VirtualPrivate Networks (RFC 4364)), VMware's NSX, GENEVE (Generic NetworkVirtualization Encapsulation), and others.

For IaaS, the infrastructure (CSPI) provided by a CSP can be configuredto provide virtualized computing resources over a public network (e.g.,the Internet). In an IaaS model, a cloud computing services provider canhost the infrastructure components (e.g., servers, storage devices,network nodes (e.g., hardware), deployment software, platformvirtualization (e.g., a hypervisor layer), or the like). In some cases,an IaaS provider may also supply a variety of services to accompanythose infrastructure components (e.g., billing, monitoring, logging,security, load balancing and clustering, etc.). Thus, as these servicesmay be policy-driven, IaaS users may be able to implement policies todrive load balancing to maintain application availability andperformance. CSPI provides infrastructure and a set of complementarycloud services that enable customers to build and run a wide range ofapplications and services in a highly available hosted distributedenvironment. CSPI offers high-performance compute resources andcapabilities and storage capacity in a flexible virtual network that issecurely accessible from various networked locations such as from acustomer's on-premises network. When a customer subscribes to orregisters for an IaaS service provided by a CSP, the tenancy created forthat customer is a secure and isolated partition within the CSPI wherethe customer can create, organize, and administer their cloud resources.

Customers can build their own virtual networks using compute, memory,and networking resources provided by CSPI. One or more customerresources or workloads, such as compute instances, can be deployed onthese virtual networks. For example, a customer can use resourcesprovided by CSPI to build one or multiple customizable and privatevirtual network(s) referred to as virtual cloud networks (VCNs). Acustomer can deploy one or more customer resources, such as computeinstances, on a customer VCN. Compute instances can take the form ofvirtual machines, bare metal instances, and the like. The CSPI thusprovides infrastructure and a set of complementary cloud services thatenable customers to build and run a wide range of applications andservices in a highly available virtual hosted environment. The customerdoes not manage or control the underlying physical resources provided byCSPI but has control over operating systems, storage, and deployedapplications; and possibly limited control of select networkingcomponents (e.g., firewalls).

The CSP may provide a console that enables customers and networkadministrators to configure, access, and manage resources deployed inthe cloud using CSPI resources. In certain embodiments, the consoleprovides a web-based user interface that can be used to access andmanage CSPI. In some implementations, the console is a web-basedapplication provided by the CSP.

CSPI may support single-tenancy or multi-tenancy architectures. In asingle tenancy architecture, a software (e.g., an application, adatabase) or a hardware component (e.g., a host machine or a server)serves a single customer or tenant. In a multi-tenancy architecture, asoftware or a hardware component serves multiple customers or tenants.Thus, in a multi-tenancy architecture, CSPI resources are shared betweenmultiple customers or tenants. In a multi-tenancy situation, precautionsare taken and safeguards put in place within CSPI to ensure that eachtenant's data is isolated and remains invisible to other tenants.

In a physical network, a network endpoint (“endpoint”) refers to acomputing device or system that is connected to a physical network andcommunicates back and forth with the network to which it is connected. Anetwork endpoint in the physical network may be connected to a LocalArea Network (LAN), a Wide Area Network (WAN), or other type of physicalnetwork. Examples of traditional endpoints in a physical network includemodems, hubs, bridges, switches, routers, and other networking devices,physical computers (or host machines), and the like. Each physicaldevice in the physical network has a fixed network address that can beused to communicate with the device. This fixed network address can be aLayer-2 address (e.g., a MAC address), a fixed Layer-3 address (e.g., anIP address), and the like. In a virtualized environment or in a virtualnetwork, the endpoints can include various virtual endpoints such asvirtual machines that are hosted by components of the physical network(e.g., hosted by physical host machines). These endpoints in the virtualnetwork are addressed by overlay addresses such as overlay Layer-2addresses (e.g., overlay MAC addresses) and overlay Layer-3 addresses(e.g., overlay IP addresses). Network overlays enable flexibility byallowing network managers to move around the overlay addressesassociated with network endpoints using software management (e.g., viasoftware implementing a control plane for the virtual network).Accordingly, unlike in a physical network, in a virtual network, anoverlay address (e.g., an overlay IP address) can be moved from oneendpoint to another using network management software. Since the virtualnetwork is built on top of a physical network, communications betweencomponents in the virtual network involves both the virtual network andthe underlying physical network. In order to facilitate suchcommunications, the components of CSPI are configured to learn and storemappings that map overlay addresses in the virtual network to actualphysical addresses in the substrate network, and vice versa. Thesemappings are then used to facilitate the communications. Customertraffic is encapsulated to facilitate routing in the virtual network.

Accordingly, physical addresses (e.g., physical IP addresses) areassociated with components in physical networks and overlay addresses(e.g., overlay IP addresses) are associated with entities in virtualnetworks. Both the physical IP addresses and overlay IP addresses aretypes of real IP addresses. These are separate from virtual IPaddresses, where a virtual IP address maps to multiple real IPaddresses. A virtual IP address provides a 1-to-many mapping between thevirtual IP address and multiple real IP addresses.

The cloud infrastructure or CSPI is physically hosted in one or moredata centers in one or more regions around the world. The CSPI mayinclude components in the physical or substrate network and virtualizedcomponents (e.g., virtual networks, compute instances, virtual machines,etc.) that are in a virtual network built on top of the physical networkcomponents. In certain embodiments, the CSPI is organized and hosted inrealms, regions and availability domains. A region is typically alocalized geographic area that contains one or more data centers.Regions are generally independent of each other and can be separated byvast distances, for example, across countries or even continents. Forexample, a first region may be in Australia, another one in Japan, yetanother one in India, and the like. CSPI resources are divided amongregions such that each region has its own independent subset of CSPIresources. Each region may provide a set of core infrastructure servicesand resources, such as, compute resources (e.g., bare metal servers,virtual machine, containers and related infrastructure, etc.); storageresources (e.g., block volume storage, file storage, object storage,archive storage); networking resources (e.g., virtual cloud networks(VCNs), load balancing resources, connections to on-premise networks),database resources; edge networking resources (e.g., DNS); and accessmanagement and monitoring resources, and others. Each region generallyhas multiple paths connecting it to other regions in the realm.

Generally, an application is deployed in a region (i.e., deployed oninfrastructure associated with that region) where it is most heavilyused, because using nearby resources is faster than using distantresources. Applications can also be deployed in different regions forvarious reasons, such as redundancy to mitigate the risk of region-wideevents such as large weather systems or earthquakes, to meet varyingrequirements for legal jurisdictions, tax domains, and other business orsocial criteria, and the like.

The data centers within a region can be further organized and subdividedinto availability domains (ADs). An availability domain may correspondto one or more data centers located within a region. A region can becomposed of one or more availability domains. In such a distributedenvironment, CSPI resources are either region-specific, such as avirtual cloud network (VCN), or availability domain-specific, such as acompute instance.

ADs within a region are isolated from each other, fault tolerant, andare configured such that they are very unlikely to fail simultaneously.This is achieved by the ADs not sharing critical infrastructureresources such as networking, physical cables, cable paths, cable entrypoints, etc., such that a failure at one AD within a region is unlikelyto impact the availability of the other ADs within the same region. TheADs within the same region may be connected to each other by a lowlatency, high bandwidth network, which makes it possible to providehigh-availability connectivity to other networks (e.g., the Internet,customers' on-premise networks, etc.) and to build replicated systems inmultiple ADs for both high-availability and disaster recovery. Cloudservices use multiple ADs to ensure high availability and to protectagainst resource failure. As the infrastructure provided by the IaaSprovider grows, more regions and ADs may be added with additionalcapacity. Traffic between availability domains is usually encrypted.

In certain embodiments, regions are grouped into realms. A realm is alogical collection of regions. Realms are isolated from each other anddo not share any data. Regions in the same realm may communicate witheach other, but regions in different realms cannot. A customer's tenancyor account with the CSP exists in a single realm and can be spreadacross one or more regions that belong to that realm. Typically, when acustomer subscribes to an IaaS service, a tenancy or account is createdfor that customer in the customer-specified region (referred to as the“home” region) within a realm. A customer can extend the customer'stenancy across one or more other regions within the realm. A customercannot access regions that are not in the realm where the customer'stenancy exists.

An IaaS provider can provide multiple realms, each realm catered to aparticular set of customers or users. For example, a commercial realmmay be provided for commercial customers. As another example, a realmmay be provided for a specific country for customers within thatcountry. As yet another example, a government realm may be provided fora government, and the like. For example, the government realm may becatered for a specific government and may have a heightened level ofsecurity than a commercial realm. For example, Oracle CloudInfrastructure (OCI) currently offers a realm for commercial regions andtwo realms (e.g., FedRAMP authorized and IL5 authorized) for governmentcloud regions.

In certain embodiments, an AD can be subdivided into one or more faultdomains. A fault domain is a grouping of infrastructure resources withinan AD to provide anti-affinity. Fault domains allow for the distributionof compute instances such that the instances are not on the samephysical hardware within a single AD. This is known as anti-affinity. Afault domain refers to a set of hardware components (computers,switches, and more) that share a single point of failure. A compute poolis logically divided up into fault domains. Due to this, a hardwarefailure or compute hardware maintenance event that affects one faultdomain does not affect instances in other fault domains. Depending onthe embodiment, the number of fault domains for each AD may vary. Forinstance, in certain embodiments each AD contains three fault domains. Afault domain acts as a logical data center within an AD.

When a customer subscribes to an IaaS service, resources from CSPI areprovisioned for the customer and associated with the customer's tenancy.The customer can use these provisioned resources to build privatenetworks and deploy resources on these networks. The customer networksthat are hosted in the cloud by the CSPI are referred to as virtualcloud networks (VCNs). A customer can set up one or more virtual cloudnetworks (VCNs) using CSPI resources allocated for the customer. A VCNis a virtual or software defined private network. The customer resourcesthat are deployed in the customer's VCN can include compute instances(e.g., virtual machines, bare-metal instances) and other resources.These compute instances may represent various customer workloads such asapplications, load balancers, databases, and the like. A computeinstance deployed on a VCN can communicate with public accessibleendpoints (“public endpoints”) over a public network such as theInternet, with other instances in the same VCN or other VCNs (e.g., thecustomer's other VCNs, or VCNs not belonging to the customer), with thecustomer's on-premise data centers or networks, and with serviceendpoints, and other types of endpoints.

The CSP may provide various services using the CSPI. In some instances,customers of CSPI may themselves act like service providers and provideservices using CSPI resources. A service provider may expose a serviceendpoint, which is characterized by identification information (e.g., anIP Address, a DNS name and port). A customer's resource (e.g., a computeinstance) can consume a particular service by accessing a serviceendpoint exposed by the service for that particular service. Theseservice endpoints are generally endpoints that are publicly accessibleby users using public IP addresses associated with the endpoints via apublic communication network such as the Internet. Network endpointsthat are publicly accessible are also sometimes referred to as publicendpoints.

In certain embodiments, a service provider may expose a service via anendpoint (sometimes referred to as a service endpoint) for the service.Customers of the service can then use this service endpoint to accessthe service. In certain implementations, a service endpoint provided fora service can be accessed by multiple customers that intend to consumethat service. In other implementations, a dedicated service endpoint maybe provided for a customer such that only that customer can access theservice using that dedicated service endpoint.

In certain embodiments, when a VCN is created, it is associated with aprivate overlay Classless Inter-Domain Routing (CIDR) address space,which is a range of private overlay IP addresses that are assigned tothe VCN (e.g., 10.0/16). A VCN includes associated subnets, routetables, and gateways. A VCN resides within a single region but can spanone or more or all of the region's availability domains. A gateway is avirtual interface that is configured for a VCN and enables communicationof traffic to and from the VCN to one or more endpoints outside the VCN.One or more different types of gateways may be configured for a VCN toenable communication to and from different types of endpoints.

A VCN can be subdivided into one or more sub-networks such as one ormore subnets. A subnet is thus a unit of configuration or a subdivisionthat can be created within a VCN. A VCN can have one or multiplesubnets. Each subnet within a VCN is associated with a contiguous rangeof overlay IP addresses (e.g., 10.0.0.0/24 and 10.0.1.0/24) that do notoverlap with other subnets in that VCN and which represent an addressspace subset within the address space of the VCN.

Each compute instance is associated with a virtual network interfacecard (VNIC) that enables the compute instance to participate in a subnetof a VCN. A VNIC is a logical representation of physical NetworkInterface Card (NIC). In general, a VNIC is an interface between anentity (e.g., a compute instance, a service) and a virtual network. AVNIC exists in a subnet, has one or more associated IP addresses, andassociated security rules or policies. A VNIC is equivalent to a Layer-2port on a switch. A VNIC is attached to a compute instance and to asubnet within a VCN. A VNIC associated with a compute instance enablesthe compute instance to be a part of a subnet of a VCN and enables thecompute instance to communicate (e.g., send and receive packets) withendpoints that are on the same subnet as the compute instance, withendpoints in different subnets in the VCN, or with endpoints outside theVCN. The VNIC associated with a compute instance thus determines how thecompute instance connects with endpoints inside and outside the VCN. AVNIC for a compute instance is created and associated with that computeinstance when the compute instance is created and added to a subnetwithin a VCN. For a subnet comprising a set of compute instances, thesubnet contains the VNICs corresponding to the set of compute instances,each VNIC attached to a compute instance within the set of computerinstances.

Each compute instance is assigned a private overlay IP address via theVNIC associated with the compute instance. This private overlay IPaddress is assigned to the VNIC that is associated with the computeinstance when the compute instance is created and used for routingtraffic to and from the compute instance. All VNICs in a given subnetuse the same route table, security lists, and DHCP options. As describedabove, each subnet within a VCN is associated with a contiguous range ofoverlay IP addresses (e.g., 10.0.0.0/24 and 10.0.1.0/24) that do notoverlap with other subnets in that VCN and which represent an addressspace subset within the address space of the VCN. For a VNIC on aparticular subnet of a VCN, the private overlay IP address that isassigned to the VNIC is an address from the contiguous range of overlayIP addresses allocated for the subnet.

In certain embodiments, a compute instance may optionally be assignedadditional overlay IP addresses in addition to the private overlay IPaddress, such as, for example, one or more public IP addresses if in apublic subnet. These multiple addresses are assigned either on the sameVNIC or over multiple VNICs that are associated with the computeinstance. Each instance however has a primary VNIC that is createdduring instance launch and is associated with the overlay private IPaddress assigned to the instance—this primary VNIC cannot be removed.Additional VNICs, referred to as secondary VNICs, can be added to anexisting instance in the same availability domain as the primary VNIC.All the VNICs are in the same availability domain as the instance. Asecondary VNIC can be in a subnet in the same VCN as the primary VNIC,or in a different subnet that is either in the same VCN or a differentone.

A compute instance may optionally be assigned a public IP address if itis in a public subnet. A subnet can be designated as either a publicsubnet or a private subnet at the time the subnet is created. A privatesubnet means that the resources (e.g., compute instances) and associatedVNICs in the subnet cannot have public overlay IP addresses. A publicsubnet means that the resources and associated VNICs in the subnet canhave public IP addresses. A customer can designate a subnet to existeither in a single availability domain or across multiple availabilitydomains in a region or realm.

As described above, a VCN may be subdivided into one or more subnets. Incertain embodiments, a Virtual Router (VR) configured for the VCN(referred to as the VCN VR or just VR) enables communications betweenthe subnets of the VCN. For a subnet within a VCN, the VR represents alogical gateway for that subnet that enables the subnet (i.e., thecompute instances on that subnet) to communicate with endpoints on othersubnets within the VCN, and with other endpoints outside the VCN. TheVCN VR is a logical entity that is configured to route traffic betweenVNICs in the VCN and virtual gateways (“gateways”) associated with theVCN. Gateways are further described below with respect to FIG. 1 . A VCNVR is a Layer-3/IP Layer concept. In one embodiment, there is one VCN VRfor a VCN where the VCN VR has potentially an unlimited number of portsaddressed by IP addresses, with one port for each subnet of the VCN. Inthis manner, the VCN VR has a different IP address for each subnet inthe VCN that the VCN VR is attached to. The VR is also connected to thevarious gateways configured for a VCN. In certain embodiments, aparticular overlay IP address from the overlay IP address range for asubnet is reserved for a port of the VCN VR for that subnet. Forexample, consider a VCN having two subnets with associated addressranges 10.0/16 and 10.1/16, respectively. For the first subnet withinthe VCN with address range 10.0/16, an address from this range isreserved for a port of the VCN VR for that subnet. In some instances,the first IP address from the range may be reserved for the VCN VR. Forexample, for the subnet with overlay IP address range 10.0/16, IPaddress 10.0.0.1 may be reserved for a port of the VCN VR for thatsubnet. For the second subnet within the same VCN with address range10.1/16, the VCN VR may have a port for that second subnet with IPaddress 10.1.0.1. The VCN VR has a different IP address for each of thesubnets in the VCN.

In some other embodiments, each subnet within a VCN may have its ownassociated VR that is addressable by the subnet using a reserved ordefault IP address associated with the VR. The reserved or default IPaddress may, for example, be the first IP address from the range of IPaddresses associated with that subnet. The VNICs in the subnet cancommunicate (e.g., send and receive packets) with the VR associated withthe subnet using this default or reserved IP address. In such anembodiment, the VR is the ingress/egress point for that subnet. The VRassociated with a subnet within the VCN can communicate with other VRsassociated with other subnets within the VCN. The VRs can alsocommunicate with gateways associated with the VCN. The VR function for asubnet is running on or executed by one or more NVDs executing VNICsfunctionality for VNICs in the subnet.

Route tables, security rules, and DHCP options may be configured for aVCN. Route tables are virtual route tables for the VCN and include rulesto route traffic from subnets within the VCN to destinations outside theVCN by way of gateways or specially configured instances. A VCN's routetables can be customized to control how packets are forwarded/routed toand from the VCN. DHCP options refers to configuration information thatis automatically provided to the instances when they boot up.

Security rules configured for a VCN represent overlay firewall rules forthe VCN. The security rules can include ingress and egress rules, andspecify the types of traffic (e.g., based upon protocol and port) thatis allowed in and out of the instances within the VCN. The customer canchoose whether a given rule is stateful or stateless. For instance, thecustomer can allow incoming SSH traffic from anywhere to a set ofinstances by setting up a stateful ingress rule with source CIDR0.0.0.0/0, and destination TCP port 22. Security rules can beimplemented using network security groups or security lists. A networksecurity group consists of a set of security rules that apply only tothe resources in that group. A security list, on the other hand,includes rules that apply to all the resources in any subnet that usesthe security list. A VCN may be provided with a default security listwith default security rules. DHCP options configured for a VCN provideconfiguration information that is automatically provided to theinstances in the VCN when the instances boot up.

In certain embodiments, the configuration information for a VCN isdetermined and stored by a VCN Control Plane. The configurationinformation for a VCN may include, for example, information about: theaddress range associated with the VCN, subnets within the VCN andassociated information, one or more VRs associated with the VCN, computeinstances in the VCN and associated VNICs, NVDs executing the variousvirtualization network functions (e.g., VNICs, VRs, gateways) associatedwith the VCN, state information for the VCN, and other VCN-relatedinformation. In certain embodiments, a VCN Distribution Servicepublishes the configuration information stored by the VCN Control Plane,or portions thereof, to the NVDs. The distributed information may beused to update information (e.g., forwarding tables, routing tables,etc.) stored and used by the NVDs to forward packets to and from thecompute instances in the VCN.

In certain embodiments, the creation of VCNs and subnets are handled bya VCN Control Plane (CP) and the launching of compute instances ishandled by a Compute Control Plane. The Compute Control Plane isresponsible for allocating the physical resources for the computeinstance and then calls the VCN Control Plane to create and attach VNICsto the compute instance. The VCN CP also sends VCN data mappings to theVCN data plane that is configured to perform packet forwarding androuting functions. In certain embodiments, the VCN CP provides adistribution service that is responsible for providing updates to theVCN data plane. Examples of a VCN Control Plane are also depicted inFIGS. 12, 13, 14, and 15 (see references 1216, 1316, 1416, and 1516) anddescribed below.

A customer may create one or more VCNs using resources hosted by CSPI. Acompute instance deployed on a customer VCN may communicate withdifferent endpoints. These endpoints can include endpoints that arehosted by CSPI and endpoints outside CSPI.

Various different architectures for implementing cloud-based serviceusing CSPI are depicted in FIGS. 1, 2, 3, 4, 5, 12, 13, 14, and 15 aredescribed below. FIG. 1 is a high level diagram of a distributedenvironment 100 showing an overlay or customer VCN hosted by CSPIaccording to certain embodiments. The distributed environment depictedin FIG. 1 includes multiple components in the overlay network.Distributed environment 100 depicted in FIG. 1 is merely an example andis not intended to unduly limit the scope of claimed embodiments. Manyvariations, alternatives, and modifications are possible. For example,in some implementations, the distributed environment depicted in FIG. 1may have more or fewer systems or components than those shown in FIG. 1, may combine two or more systems, or may have a different configurationor arrangement of systems.

As shown in the example depicted in FIG. 1 , distributed environment 100comprises CSPI 101 that provides services and resources that customerscan subscribe to and use to build their virtual cloud networks (VCNs).In certain embodiments, CSPI 101 offers IaaS services to subscribingcustomers. The data centers within CSPI 101 may be organized into one ormore regions. One example region “Region US” 102 is shown in FIG. 1 . Acustomer has configured a customer VCN 104 for region 102. The customermay deploy various compute instances on VCN 104, where the computeinstances may include virtual machines or bare metal instances. Examplesof instances include applications, database, load balancers, and thelike.

In the embodiment depicted in FIG. 1 , customer VCN 104 comprises twosubnets, namely, “Subnet-1” and “Subnet-2”, each subnet with its ownCIDR IP address range. In FIG. 1 , the overlay IP address range forSubnet-1 is 10.0/16 and the address range for Subnet-2 is 10.1/16. A VCNVirtual Router 105 represents a logical gateway for the VCN that enablescommunications between subnets of the VCN 104, and with other endpointsoutside the VCN. VCN VR 105 is configured to route traffic between VNICsin VCN 104 and gateways associated with VCN 104. VCN VR 105 provides aport for each subnet of VCN 104. For example, VR 105 may provide a portwith IP address 10.0.0.1 for Subnet-1 and a port with IP address10.1.0.1 for Subnet-2.

Multiple compute instances may be deployed on each subnet, where thecompute instances can be virtual machine instances, and/or bare metalinstances. The compute instances in a subnet may be hosted by one ormore host machines within CSPI 101. A compute instance participates in asubnet via a VNIC associated with the compute instance. For example, asshown in FIG. 1 , a compute instance C1 is part of Subnet-1 via a VNICassociated with the compute instance. Likewise, compute instance C2 ispart of Subnet-1 via a VNIC associated with C2. In a similar manner,multiple compute instances, which may be virtual machine instances orbare metal instances, may be part of Subnet-1. Via its associated VNIC,each compute instance is assigned a private overlay IP address and a MACaddress. For example, in FIG. 1 , compute instance C1 has an overlay IPaddress of 10.0.0.2 and a MAC address of M1, while compute instance C2has a private overlay IP address of 10.0.0.3 and a MAC address of M2.Each compute instance in Subnet-1, including compute instances C1 andC2, has a default route to VCN VR 105 using IP address 10.0.0.1, whichis the IP address for a port of VCN VR 105 for Subnet-1.

Subnet-2 can have multiple compute instances deployed on it, includingvirtual machine instances and/or bare metal instances. For example, asshown in FIG. 1 , compute instances D1 and D2 are part of Subnet-2 viaVNICs associated with the respective compute instances. In theembodiment depicted in FIG. 1 , compute instance D1 has an overlay IPaddress of 10.1.0.2 and a MAC address of MM1, while compute instance D2has an private overlay IP address of 10.1.0.3 and a MAC address of MM2.Each compute instance in Subnet-2, including compute instances D1 andD2, has a default route to VCN VR 105 using IP address 10.1.0.1, whichis the IP address for a port of VCN VR 105 for Subnet-2.

VCN A 104 may also include one or more load balancers. For example, aload balancer may be provided for a subnet and may be configured to loadbalance traffic across multiple compute instances on the subnet. A loadbalancer may also be provided to load balance traffic across subnets inthe VCN.

A particular compute instance deployed on VCN 104 can communicate withvarious different endpoints. These endpoints may include endpoints thatare hosted by CSPI 200 and endpoints outside CSPI 200. Endpoints thatare hosted by CSPI 101 may include: an endpoint on the same subnet asthe particular compute instance (e.g., communications between twocompute instances in Subnet-1); an endpoint on a different subnet butwithin the same VCN (e.g., communication between a compute instance inSubnet-1 and a compute instance in Subnet-2); an endpoint in a differentVCN in the same region (e.g., communications between a compute instancein Subnet-1 and an endpoint in a VCN in the same region 106 or 110,communications between a compute instance in Subnet-1 and an endpoint inservice network 110 in the same region); or an endpoint in a VCN in adifferent region (e.g., communications between a compute instance inSubnet-1 and an endpoint in a VCN in a different region 108). A computeinstance in a subnet hosted by CSPI 101 may also communicate withendpoints that are not hosted by CSPI 101 (i.e., are outside CSPI 101).These outside endpoints include endpoints in the customer's on-premisenetwork 116, endpoints within other remote cloud hosted networks 118,public endpoints 114 accessible via a public network such as theInternet, and other endpoints.

Communications between compute instances on the same subnet arefacilitated using VNICs associated with the source compute instance andthe destination compute instance. For example, compute instance C1 inSubnet-1 may want to send packets to compute instance C2 in Subnet-1.For a packet originating at a source compute instance and whosedestination is another compute instance in the same subnet, the packetis first processed by the VNIC associated with the source computeinstance. Processing performed by the VNIC associated with the sourcecompute instance can include determining destination information for thepacket from the packet headers, identifying any policies (e.g., securitylists) configured for the VNIC associated with the source computeinstance, determining a next hop for the packet, performing any packetencapsulation/decapsulation functions as needed, and thenforwarding/routing the packet to the next hop with the goal offacilitating communication of the packet to its intended destination.When the destination compute instance is in the same subnet as thesource compute instance, the VNIC associated with the source computeinstance is configured to identify the VNIC associated with thedestination compute instance and forward the packet to that VNIC forprocessing. The VNIC associated with the destination compute instance isthen executed and forwards the packet to the destination computeinstance.

For a packet to be communicated from a compute instance in a subnet toan endpoint in a different subnet in the same VCN, the communication isfacilitated by the VNICs associated with the source and destinationcompute instances and the VCN VR. For example, if compute instance C1 inSubnet-1 in FIG. 1 wants to send a packet to compute instance D1 inSubnet-2, the packet is first processed by the VNIC associated withcompute instance C1. The VNIC associated with compute instance C1 isconfigured to route the packet to the VCN VR 105 using default route orport 10.0.0.1 of the VCN VR. VCN VR 105 is configured to route thepacket to Subnet-2 using port 10.1.0.1. The packet is then received andprocessed by the VNIC associated with D1 and the VNIC forwards thepacket to compute instance D1.

For a packet to be communicated from a compute instance in VCN 104 to anendpoint that is outside VCN 104, the communication is facilitated bythe VNIC associated with the source compute instance, VCN VR 105, andgateways associated with VCN 104. One or more types of gateways may beassociated with VCN 104. A gateway is an interface between a VCN andanother endpoint, where the another endpoint is outside the VCN. Agateway is a Layer-3/IP layer concept and enables a VCN to communicatewith endpoints outside the VCN. A gateway thus facilitates traffic flowbetween a VCN and other VCNs or networks. Various different types ofgateways may be configured for a VCN to facilitate different types ofcommunications with different types of endpoints. Depending upon thegateway, the communications may be over public networks (e.g., theInternet) or over private networks. Various communication protocols maybe used for these communications.

For example, compute instance C1 may want to communicate with anendpoint outside VCN 104. The packet may be first processed by the VNICassociated with source compute instance C1. The VNIC processingdetermines that the destination for the packet is outside the Subnet-1of C1. The VNIC associated with C1 may forward the packet to VCN VR 105for VCN 104. VCN VR 105 then processes the packet and as part of theprocessing, based upon the destination for the packet, determines aparticular gateway associated with VCN 104 as the next hop for thepacket. VCN VR 105 may then forward the packet to the particularidentified gateway. For example, if the destination is an endpointwithin the customer's on-premise network, then the packet may beforwarded by VCN VR 105 to Dynamic Routing Gateway (DRG) gateway 122configured for VCN 104. The packet may then be forwarded from thegateway to a next hop to facilitate communication of the packet to itfinal intended destination.

Various different types of gateways may be configured for a VCN.Examples of gateways that may be configured for a VCN are depicted inFIG. 1 and described below. Examples of gateways associated with a VCNare also depicted in FIGS. 12, 13, 14, and 15 (for example, gatewaysreferenced by reference numbers 1234, 1236, 1238, 1334, 1336, 1338,1434, 1436, 1438, 1534, 1536, and 1538) and described below. As shown inthe embodiment depicted in FIG. 1 , a Dynamic Routing Gateway (DRG) 122may be added to or be associated with customer VCN 104 and provides apath for private network traffic communication between customer VCN 104and another endpoint, where the another endpoint can be the customer'son-premise network 116, a VCN 108 in a different region of CSPI 101, orother remote cloud networks 118 not hosted by CSPI 101. Customeron-premise network 116 may be a customer network or a customer datacenter built using the customer's resources. Access to customeron-premise network 116 is generally very restricted. For a customer thathas both a customer on-premise network 116 and one or more VCNs 104deployed or hosted in the cloud by CSPI 101, the customer may want theiron-premise network 116 and their cloud-based VCN 104 to be able tocommunicate with each other. This enables a customer to build anextended hybrid environment encompassing the customer's VCN 104 hostedby CSPI 101 and their on-premises network 116. DRG 122 enables thiscommunication. To enable such communications, a communication channel124 is set up where one endpoint of the channel is in customeron-premise network 116 and the other endpoint is in CSPI 101 andconnected to customer VCN 104. Communication channel 124 can be overpublic communication networks such as the Internet or privatecommunication networks. Various different communication protocols may beused such as IPsec VPN technology over a public communication networksuch as the Internet, Oracle's FastConnect technology that uses aprivate network instead of a public network, and others. The device orequipment in customer on-premise network 116 that forms one end pointfor communication channel 124 is referred to as the customer premiseequipment (CPE), such as CPE 126 depicted in FIG. 1 . On the CSPI 101side, the endpoint may be a host machine executing DRG 122.

In certain embodiments, a Remote Peering Connection (RPC) can be addedto a DRG, which allows a customer to peer one VCN with another VCN in adifferent region. Using such an RPC, customer VCN 104 can use DRG 122 toconnect with a VCN 108 in another region. DRG 122 may also be used tocommunicate with other remote cloud networks 118, not hosted by CSPI 101such as a Microsoft Azure cloud, Amazon AWS cloud, and others.

As shown in FIG. 1 , an Internet Gateway (IGW) 120 may be configured forcustomer VCN 104 the enables a compute instance on VCN 104 tocommunicate with public endpoints 114 accessible over a public networksuch as the Internet. IGW 1120 is a gateway that connects a VCN to apublic network such as the Internet. IGW 120 enables a public subnet(where the resources in the public subnet have public overlay IPaddresses) within a VCN, such as VCN 104, direct access to publicendpoints 112 on a public network 114 such as the Internet. Using IGW120, connections can be initiated from a subnet within VCN 104 or fromthe Internet.

A Network Address Translation (NAT) gateway 128 can be configured forcustomer's VCN 104 and enables cloud resources in the customer's VCN,which do not have dedicated public overlay IP addresses, access to theInternet and it does so without exposing those resources to directincoming Internet connections (e.g., L4-L7 connections). This enables aprivate subnet within a VCN, such as private Subnet-1 in VCN 104, withprivate access to public endpoints on the Internet. In NAT gateways,connections can be initiated only from the private subnet to the publicInternet and not from the Internet to the private subnet.

In certain embodiments, a Service Gateway (SGW) 126 can be configuredfor customer VCN 104 and provides a path for private network trafficbetween VCN 104 and supported services endpoints in a service network110. In certain embodiments, service network 110 may be provided by theCSP and may provide various services. An example of such a servicenetwork is Oracle's Services Network, which provides various servicesthat can be used by customers. For example, a compute instance (e.g., adatabase system) in a private subnet of customer VCN 104 can back updata to a service endpoint (e.g., Object Storage) without needing publicIP addresses or access to the Internet. In certain embodiments, a VCNcan have only one SGW, and connections can only be initiated from asubnet within the VCN and not from service network 110. If a VCN ispeered with another, resources in the other VCN typically cannot accessthe SGW. Resources in on-premises networks that are connected to a VCNwith FastConnect or VPN Connect can also use the service gatewayconfigured for that VCN.

In certain implementations, SGW 126 uses the concept of a serviceClassless Inter-Domain Routing (CIDR) label, which is a string thatrepresents all the regional public IP address ranges for the service orgroup of services of interest. The customer uses the service CIDR labelwhen they configure the SGW and related route rules to control trafficto the service. The customer can optionally utilize it when configuringsecurity rules without needing to adjust them if the service's public IPaddresses change in the future.

A Local Peering Gateway (LPG) 132 is a gateway that can be added tocustomer VCN 104 and enables VCN 104 to peer with another VCN in thesame region. Peering means that the VCNs communicate using private IPaddresses, without the traffic traversing a public network such as theInternet or without routing the traffic through the customer'son-premises network 116. In preferred embodiments, a VCN has a separateLPG for each peering it establishes. Local Peering or VCN Peering is acommon practice used to establish network connectivity between differentapplications or infrastructure management functions.

Service providers, such as providers of services in service network 110,may provide access to services using different access models. Accordingto a public access model, services may be exposed as public endpointsthat are publicly accessible by compute instance in a customer VCN via apublic network such as the Internet and or may be privately accessiblevia SGW 126. According to a specific private access model, services aremade accessible as private IP endpoints in a private subnet in thecustomer's VCN. This is referred to as a Private Endpoint (PE) accessand enables a service provider to expose their service as an instance inthe customer's private network. A Private Endpoint resource represents aservice within the customer's VCN. Each PE manifests as a VNIC (referredto as a PE-VNIC, with one or more private IPs) in a subnet chosen by thecustomer in the customer's VCN. A PE thus provides a way to present aservice within a private customer VCN subnet using a VNIC. Since theendpoint is exposed as a VNIC, all the features associates with a VNICsuch as routing rules, security lists, etc., are now available for thePE VNIC.

A service provider can register their service to enable access through aPE. The provider can associate policies with the service that restrictsthe service's visibility to the customer tenancies. A provider canregister multiple services under a single virtual IP address (VIP),especially for multi-tenant services. There may be multiple such privateendpoints (in multiple VCNs) that represent the same service.

Compute instances in the private subnet can then use the PE VNIC'sprivate IP address or the service DNS name to access the service.Compute instances in the customer VCN can access the service by sendingtraffic to the private IP address of the PE in the customer VCN. APrivate Access Gateway (PAGW) 130 is a gateway resource that can beattached to a service provider VCN (e.g., a VCN in service network 110)that acts as an ingress/egress point for all traffic from/to customersubnet private endpoints. PAGW 130 enables a provider to scale thenumber of PE connections without utilizing its internal IP addressresources. A provider needs only configure one PAGW for any number ofservices registered in a single VCN. Providers can represent a serviceas a private endpoint in multiple VCNs of one or more customers. Fromthe customer's perspective, the PE VNIC, which, instead of beingattached to a customer's instance, appears attached to the service withwhich the customer wishes to interact. The traffic destined to theprivate endpoint is routed via PAGW 130 to the service. These arereferred to as customer-to-service private connections (C2Sconnections).

The PE concept can also be used to extend the private access for theservice to customer's on-premises networks and data centers, by allowingthe traffic to flow through FastConnect/IPsec links and the privateendpoint in the customer VCN. Private access for the service can also beextended to the customer's peered VCNs, by allowing the traffic to flowbetween LPG 132 and the PE in the customer's VCN.

A customer can control routing in a VCN at the subnet level, so thecustomer can specify which subnets in the customer's VCN, such as VCN104, use each gateway. A VCN's route tables are used to decide iftraffic is allowed out of a VCN through a particular gateway. Forexample, in a particular instance, a route table for a public subnetwithin customer VCN 104 may send non-local traffic through IGW 120. Theroute table for a private subnet within the same customer VCN 104 maysend traffic destined for CSP services through SGW 126. All remainingtraffic may be sent via the NAT gateway 128. Route tables only controltraffic going out of a VCN.

Security lists associated with a VCN are used to control traffic thatcomes into a VCN via a gateway via inbound connections. All resources ina subnet use the same route table and security lists. Security lists maybe used to control specific types of traffic allowed in and out ofinstances in a subnet of a VCN. Security list rules may comprise ingress(inbound) and egress (outbound) rules. For example, an ingress rule mayspecify an allowed source address range, while an egress rule mayspecify an allowed destination address range. Security rules may specifya particular protocol (e.g., TCP, ICMP), a particular port (e.g., 22 forSSH, 3389 for Windows RDP), etc. In certain implementations, aninstance's operating system may enforce its own firewall rules that arealigned with the security list rules. Rules may be stateful (e.g., aconnection is tracked and the response is automatically allowed withoutan explicit security list rule for the response traffic) or stateless.

Access from a customer VCN (i.e., by a resource or compute instancedeployed on VCN 104) can be categorized as public access, privateaccess, or dedicated access. Public access refers to an access modelwhere a public IP address or a NAT is used to access a public endpoint.Private access enables customer workloads in VCN 104 with private IPaddresses (e.g., resources in a private subnet) to access serviceswithout traversing a public network such as the Internet. In certainembodiments, CSPI 101 enables customer VCN workloads with private IPaddresses to access the (public service endpoints of) services using aservice gateway. A service gateway thus offers a private access model byestablishing a virtual link between the customer's VCN and the service'spublic endpoint residing outside the customer's private network.

Additionally, CSPI may offer dedicated public access using technologiessuch as FastConnect public peering where customer on-premises instancescan access one or more services in a customer VCN using a FastConnectconnection and without traversing a public network such as the Internet.CSPI also may also offer dedicated private access using FastConnectprivate peering where customer on-premises instances with private IPaddresses can access the customer's VCN workloads using a FastConnectconnection. FastConnect is a network connectivity alternative to usingthe public Internet to connect a customer's on-premise network to CSPIand its services. FastConnect provides an easy, elastic, and economicalway to create a dedicated and private connection with higher bandwidthoptions and a more reliable and consistent networking experience whencompared to Internet-based connections.

FIG. 1 and the accompanying description above describes variousvirtualized components in an example virtual network. As describedabove, the virtual network is built on the underlying physical orsubstrate network. FIG. 2 depicts a simplified architectural diagram ofthe physical components in the physical network within CSPI 200 thatprovide the underlay for the virtual network according to certainembodiments. As shown, CSPI 200 provides a distributed environmentcomprising components and resources (e.g., compute, memory, andnetworking resources) provided by a cloud service provider (CSP). Thesecomponents and resources are used to provide cloud services (e.g., IaaSservices) to subscribing customers, i.e., customers that have subscribedto one or more services provided by the CSP. Based upon the servicessubscribed to by a customer, a subset of resources (e.g., compute,memory, and networking resources) of CSPI 200 are provisioned for thecustomer. Customers can then build their own cloud-based (i.e.,CSPI-hosted) customizable and private virtual networks using physicalcompute, memory, and networking resources provided by CSPI 200. Aspreviously indicated, these customer networks are referred to as virtualcloud networks (VCNs). A customer can deploy one or more customerresources, such as compute instances, on these customer VCNs. Computeinstances can be in the form of virtual machines, bare metal instances,and the like. CSPI 200 provides infrastructure and a set ofcomplementary cloud services that enable customers to build and run awide range of applications and services in a highly available hostedenvironment.

In the example embodiment depicted in FIG. 2 , the physical componentsof CSPI 200 include one or more physical host machines or physicalservers (e.g., 202, 206, 208), network virtualization devices (NVDs)(e.g., 210, 212), top-of-rack (TOR) switches (e.g., 214, 216), and aphysical network (e.g., 218), and switches in physical network 218. Thephysical host machines or servers may host and execute various computeinstances that participate in one or more subnets of a VCN. The computeinstances may include virtual machine instances, and bare metalinstances. For example, the various compute instances depicted in FIG. 1may be hosted by the physical host machines depicted in FIG. 2 . Thevirtual machine compute instances in a VCN may be executed by one hostmachine or by multiple different host machines. The physical hostmachines may also host virtual host machines, container-based hosts orfunctions, and the like. The VNICs and VCN VR depicted in FIG. 1 may beexecuted by the NVDs depicted in FIG. 2 . The gateways depicted in FIG.1 may be executed by the host machines and/or by the NVDs depicted inFIG. 2 .

The host machines or servers may execute a hypervisor (also referred toas a virtual machine monitor or VMM) that creates and enables avirtualized environment on the host machines. The virtualization orvirtualized environment facilitates cloud-based computing. One or morecompute instances may be created, executed, and managed on a hostmachine by a hypervisor on that host machine. The hypervisor on a hostmachine enables the physical computing resources of the host machine(e.g., compute, memory, and networking resources) to be shared betweenthe various compute instances executed by the host machine.

For example, as depicted in FIG. 2 , host machines 202 and 208 executehypervisors 260 and 266, respectively. These hypervisors may beimplemented using software, firmware, or hardware, or combinationsthereof. Typically, a hypervisor is a process or a software layer thatsits on top of the host machine's operating system (OS), which in turnexecutes on the hardware processors of the host machine. The hypervisorprovides a virtualized environment by enabling the physical computingresources (e.g., processing resources such as processors/cores, memoryresources, networking resources) of the host machine to be shared amongthe various virtual machine compute instances executed by the hostmachine. For example, in FIG. 2 , hypervisor 260 may sit on top of theOS of host machine 202 and enables the computing resources (e.g.,processing, memory, and networking resources) of host machine 202 to beshared between compute instances (e.g., virtual machines) executed byhost machine 202. A virtual machine can have its own operating system(referred to as a guest operating system), which may be the same as ordifferent from the OS of the host machine. The operating system of avirtual machine executed by a host machine may be the same as ordifferent from the operating system of another virtual machine executedby the same host machine. A hypervisor thus enables multiple operatingsystems to be executed alongside each other while sharing the samecomputing resources of the host machine. The host machines depicted inFIG. 2 may have the same or different types of hypervisors.

A compute instance can be a virtual machine instance or a bare metalinstance. In FIG. 2 , compute instances 268 on host machine 202 and 274on host machine 208 are examples of virtual machine instances. Hostmachine 206 is an example of a bare metal instance that is provided to acustomer.

In certain instances, an entire host machine may be provisioned to asingle customer, and all of the one or more compute instances (eithervirtual machines or bare metal instance) hosted by that host machinebelong to that same customer. In other instances, a host machine may beshared between multiple customers (i.e., multiple tenants). In such amulti-tenancy scenario, a host machine may host virtual machine computeinstances belonging to different customers. These compute instances maybe members of different VCNs of different customers. In certainembodiments, a bare metal compute instance is hosted by a bare metalserver without a hypervisor. When a bare metal compute instance isprovisioned, a single customer or tenant maintains control of thephysical CPU, memory, and network interfaces of the host machine hostingthe bare metal instance and the host machine is not shared with othercustomers or tenants.

As previously described, each compute instance that is part of a VCN isassociated with a VNIC that enables the compute instance to become amember of a subnet of the VCN. The VNIC associated with a computeinstance facilitates the communication of packets or frames to and fromthe compute instance. A VNIC is associated with a compute instance whenthe compute instance is created. In certain embodiments, for a computeinstance executed by a host machine, the VNIC associated with thatcompute instance is executed by an NVD connected to the host machine.For example, in FIG. 2 , host machine 202 executes a virtual machinecompute instance 268 that is associated with VNIC 276, and VNIC 276 isexecuted by NVD 210 connected to host machine 202. As another example,bare metal instance 272 hosted by host machine 206 is associated withVNIC 280 that is executed by NVD 212 connected to host machine 206. Asyet another example, VNIC 284 is associated with compute instance 274executed by host machine 208, and VNIC 284 is executed by NVD 212connected to host machine 208.

For compute instances hosted by a host machine, an NVD connected to thathost machine also executes VCN VRs corresponding to VCNs of which thecompute instances are members. For example, in the embodiment depictedin FIG. 2 , NVD 210 executes VCN VR 277 corresponding to the VCN ofwhich compute instance 268 is a member. NVD 212 may also execute one ormore VCN VRs 283 corresponding to VCNs corresponding to the computeinstances hosted by host machines 206 and 208.

A host machine may include one or more network interface cards (NIC)that enable the host machine to be connected to other devices. A NIC ona host machine may provide one or more ports (or interfaces) that enablethe host machine to be communicatively connected to another device. Forexample, a host machine may be connected to an NVD using one or moreports (or interfaces) provided on the host machine and on the NVD. Ahost machine may also be connected to other devices such as another hostmachine.

For example, in FIG. 2 , host machine 202 is connected to NVD 210 usinglink 220 that extends between a port 234 provided by a NIC 232 of hostmachine 202 and between a port 236 of NVD 210. Host machine 206 isconnected to NVD 212 using link 224 that extends between a port 246provided by a NIC 244 of host machine 206 and between a port 248 of NVD212. Host machine 208 is connected to NVD 212 using link 226 thatextends between a port 252 provided by a NIC 250 of host machine 208 andbetween a port 254 of NVD 212.

The NVDs are in turn connected via communication links totop-of-the-rack (TOR) switches, which are connected to physical network218 (also referred to as the switch fabric). In certain embodiments, thelinks between a host machine and an NVD, and between an NVD and a TORswitch are Ethernet links. For example, in FIG. 2 , NVDs 210 and 212 areconnected to TOR switches 214 and 216, respectively, using links 228 and230. In certain embodiments, the links 220, 224, 226, 228, and 230 areEthernet links. The collection of host machines and NVDs that areconnected to a TOR is sometimes referred to as a rack.

Physical network 218 provides a communication fabric that enables TORswitches to communicate with each other. Physical network 218 can be amulti-tiered network. In certain implementations, physical network 218is a multi-tiered Clos network of switches, with TOR switches 214 and216 representing the leaf level nodes of the multi-tiered and multi-nodephysical switching network 218. Different Clos network configurationsare possible including but not limited to a 2-tier network, a 3-tiernetwork, a 4-tier network, a 5-tier network, and in general a “n”-tierednetwork. An example of a Clos network is depicted in FIG. 5 anddescribed below.

Various different connection configurations are possible between hostmachines and NVDs such as one-to-one configuration, many-to-oneconfiguration, one-to-many configuration, and others. In a one-to-oneconfiguration implementation, each host machine is connected to its ownseparate NVD. For example, in FIG. 2 , host machine 202 is connected toNVD 210 via NIC 232 of host machine 202. In a many-to-one configuration,multiple host machines are connected to one NVD. For example, in FIG. 2, host machines 206 and 208 are connected to the same NVD 212 via NICs244 and 250, respectively.

In a one-to-many configuration, one host machine is connected tomultiple NVDs. FIG. 3 shows an example within CSPI 300 where a hostmachine is connected to multiple NVDs. As shown in FIG. 3 , host machine302 comprises a network interface card (NIC) 304 that includes multipleports 306 and 308. Host machine 300 is connected to a first NVD 310 viaport 306 and link 320, and connected to a second NVD 312 via port 308and link 322. Ports 306 and 308 may be Ethernet ports and the links 320and 322 between host machine 302 and NVDs 310 and 312 may be Ethernetlinks. NVD 310 is in turn connected to a first TOR switch 314 and NVD312 is connected to a second TOR switch 316. The links between NVDs 310and 312, and TOR switches 314 and 316 may be Ethernet links. TORswitches 314 and 316 represent the Tier-0 switching devices inmulti-tiered physical network 318.

The arrangement depicted in FIG. 3 provides two separate physicalnetwork paths to and from physical switch network 318 to host machine302: a first path traversing TOR switch 314 to NVD 310 to host machine302, and a second path traversing TOR switch 316 to NVD 312 to hostmachine 302. The separate paths provide for enhanced availability(referred to as high availability) of host machine 302. If there areproblems in one of the paths (e.g., a link in one of the paths goesdown) or devices (e.g., a particular NVD is not functioning), then theother path may be used for communications to/from host machine 302.

In the configuration depicted in FIG. 3 , the host machine is connectedto two different NVDs using two different ports provided by a NIC of thehost machine. In other embodiments, a host machine may include multipleNICs that enable connectivity of the host machine to multiple NVDs.

Referring back to FIG. 2 , an NVD is a physical device or component thatperforms one or more network and/or storage virtualization functions. AnNVD may be any device with one or more processing units (e.g., CPUs,Network Processing Units (NPUs), FPGAs, packet processing pipelines,etc.), memory including cache, and ports. The various virtualizationfunctions may be performed by software/firmware executed by the one ormore processing units of the NVD.

An NVD may be implemented in various different forms. For example, incertain embodiments, an NVD is implemented as an interface card referredto as a smartNIC or an intelligent MC with an embedded processoronboard. A smartNIC is a separate device from the NICs on the hostmachines. In FIG. 2 , the NVDs 210 and 212 may be implemented assmartNICs that are connected to host machines 202, and host machines 206and 208, respectively.

A smartNIC is however just one example of an NVD implementation. Variousother implementations are possible. For example, in some otherimplementations, an NVD or one or more functions performed by the NVDmay be incorporated into or performed by one or more host machines, oneor more TOR switches, and other components of CSPI 200. For example, anNVD may be embodied in a host machine where the functions performed byan NVD are performed by the host machine. As another example, an NVD maybe part of a TOR switch or a TOR switch may be configured to performfunctions performed by an NVD that enables the TOR switch to performvarious complex packet transformations that are used for a public cloud.A TOR that performs the functions of an NVD is sometimes referred to asa smart TOR. In yet other implementations, where virtual machines (VMs)instances, but not bare metal (BM) instances, are offered to customers,functions performed by an NVD may be implemented inside a hypervisor ofthe host machine. In some other implementations, some of the functionsof the NVD may be offloaded to a centralized service running on a fleetof host machines.

In certain embodiments, such as when implemented as a smartNIC as shownin FIG. 2 , an NVD may comprise multiple physical ports that enable itto be connected to one or more host machines and to one or more TORswitches. A port on an NVD can be classified as a host-facing port (alsoreferred to as a “south port”) or a network-facing or TOR-facing port(also referred to as a “north port”). A host-facing port of an NVD is aport that is used to connect the NVD to a host machine. Examples ofhost-facing ports in FIG. 2 include port 236 on NVD 210, and ports 248and 254 on NVD 212. A network-facing port of an NVD is a port that isused to connect the NVD to a TOR switch. Examples of network-facingports in FIG. 2 include port 256 on NVD 210, and port 258 on NVD 212. Asshown in FIG. 2 , NVD 210 is connected to TOR switch 214 using link 228that extends from port 256 of NVD 210 to the TOR switch 214. Likewise,NVD 212 is connected to TOR switch 216 using link 230 that extends fromport 258 of NVD 212 to the TOR switch 216.

An NVD receives packets and frames from a host machine (e.g., packetsand frames generated by a compute instance hosted by the host machine)via a host-facing port and, after performing the necessary packetprocessing, may forward the packets and frames to a TOR switch via anetwork-facing port of the NVD. An NVD may receive packets and framesfrom a TOR switch via a network-facing port of the NVD and, afterperforming the necessary packet processing, may forward the packets andframes to a host machine via a host-facing port of the NVD.

In certain embodiments, there may be multiple ports and associated linksbetween an NVD and a TOR switch. These ports and links may be aggregatedto form a link aggregator group of multiple ports or links (referred toas a LAG). Link aggregation allows multiple physical links between twoend-points (e.g., between an NVD and a TOR switch) to be treated as asingle logical link. All the physical links in a given LAG may operatein full-duplex mode at the same speed. LAGs help increase the bandwidthand reliability of the connection between two endpoints. If one of thephysical links in the LAG goes down, traffic is dynamically andtransparently reassigned to one of the other physical links in the LAG.The aggregated physical links deliver higher bandwidth than eachindividual link. The multiple ports associated with a LAG are treated asa single logical port. Traffic can be load-balanced across the multiplephysical links of a LAG. One or more LAGs may be configured between twoendpoints. The two endpoints may be between an NVD and a TOR switch,between a host machine and an NVD, and the like.

An NVD implements or performs network virtualization functions. Thesefunctions are performed by software/firmware executed by the NVD.Examples of network virtualization functions include without limitation:packet encapsulation and de-capsulation functions; functions forcreating a VCN network; functions for implementing network policies suchas VCN security list (firewall) functionality; functions that facilitatethe routing and forwarding of packets to and from compute instances in aVCN; and the like. In certain embodiments, upon receiving a packet, anNVD is configured to execute a packet processing pipeline for processingthe packet and determining how the packet is to be forwarded or routed.As part of this packet processing pipeline, the NVD may execute one ormore virtual functions associated with the overlay network such asexecuting VNICs associated with cis in the VCN, executing a VirtualRouter (VR) associated with the VCN, the encapsulation and decapsulationof packets to facilitate forwarding or routing in the virtual network,execution of certain gateways (e.g., the Local Peering Gateway), theimplementation of Security Lists, Network Security Groups, networkaddress translation (NAT) functionality (e.g., the translation of PublicIP to Private IP on a host by host basis), throttling functions, andother functions.

In certain embodiments, the packet processing data path in an NVD maycomprise multiple packet pipelines, each composed of a series of packettransformation stages. In certain implementations, upon receiving apacket, the packet is parsed and classified to a single pipeline. Thepacket is then processed in a linear fashion, one stage after another,until the packet is either dropped or sent out over an interface of theNVD. These stages provide basic functional packet processing buildingblocks (e.g., validating headers, enforcing throttle, inserting newLayer-2 headers, enforcing L4 firewall, VCN encapsulation/decapsulation,etc.) so that new pipelines can be constructed by composing existingstages, and new functionality can be added by creating new stages andinserting them into existing pipelines.

An NVD may perform both control plane and data plane functionscorresponding to a control plane and a data plane of a VCN. Examples ofa VCN Control Plane are also depicted in FIGS. 12, 13, 14, and 15 (seereferences 1216, 1316, 1416, and 1516) and described below. Examples ofa VCN Data Plane are depicted in FIGS. 12, 13, 14, and 15 (seereferences 1218, 1318, 1418, and 1518) and described below. The controlplane functions include functions used for configuring a network (e.g.,setting up routes and route tables, configuring VNICs, etc.) thatcontrols how data is to be forwarded. In certain embodiments, a VCNControl Plane is provided that computes all the overlay-to-substratemappings centrally and publishes them to the NVDs and to the virtualnetwork edge devices such as various gateways such as the DRG, the SGW,the IGW, etc. Firewall rules may also be published using the samemechanism. In certain embodiments, an NVD only gets the mappings thatare relevant for that NVD. The data plane functions include functionsfor the actual routing/forwarding of a packet based upon configurationset up using control plane. A VCN data plane is implemented byencapsulating the customer's network packets before they traverse thesubstrate network. The encapsulation/decapsulation functionality isimplemented on the NVDs. In certain embodiments, an NVD is configured tointercept all network packets in and out of host machines and performnetwork virtualization functions.

As indicated above, an NVD executes various virtualization functionsincluding VNICs and VCN VRs. An NVD may execute VNICs associated withthe compute instances hosted by one or more host machines connected tothe VNIC. For example, as depicted in FIG. 2 , NVD 210 executes thefunctionality for VNIC 276 that is associated with compute instance 268hosted by host machine 202 connected to NVD 210. As another example, NVD212 executes VNIC 280 that is associated with bare metal computeinstance 272 hosted by host machine 206, and executes VNIC 284 that isassociated with compute instance 274 hosted by host machine 208. A hostmachine may host compute instances belonging to different VCNs, whichbelong to different customers, and the NVD connected to the host machinemay execute the VNICs (i.e., execute VNICs-relate functionality)corresponding to the compute instances.

An NVD also executes VCN Virtual Routers corresponding to the VCNs ofthe compute instances. For example, in the embodiment depicted in FIG. 2, NVD 210 executes VCN VR 277 corresponding to the VCN to which computeinstance 268 belongs. NVD 212 executes one or more VCN VRs 283corresponding to one or more VCNs to which compute instances hosted byhost machines 206 and 208 belong. In certain embodiments, the VCN VRcorresponding to that VCN is executed by all the NVDs connected to hostmachines that host at least one compute instance belonging to that VCN.If a host machine hosts compute instances belonging to different VCNs,an NVD connected to that host machine may execute VCN VRs correspondingto those different VCNs.

In addition to VNICs and VCN VRs, an NVD may execute various software(e.g., daemons) and include one or more hardware components thatfacilitate the various network virtualization functions performed by theNVD. For purposes of simplicity, these various components are groupedtogether as “packet processing components” shown in FIG. 2 . Forexample, NVD 210 comprises packet processing components 286 and NVD 212comprises packet processing components 288. For example, the packetprocessing components for an NVD may include a packet processor that isconfigured to interact with the NVD's ports and hardware interfaces tomonitor all packets received by and communicated using the NVD and storenetwork information. The network information may, for example, includenetwork flow information identifying different network flows handled bythe NVD and per flow information (e.g., per flow statistics). In certainembodiments, network flows information may be stored on a per VNICbasis. The packet processor may perform packet-by-packet manipulationsas well as implement stateful NAT and L4 firewall (FW). As anotherexample, the packet processing components may include a replicationagent that is configured to replicate information stored by the NVD toone or more different replication target stores. As yet another example,the packet processing components may include a logging agent that isconfigured to perform logging functions for the NVD. The packetprocessing components may also include software for monitoring theperformance and health of the NVD and, also possibly of monitoring thestate and health of other components connected to the NVD.

FIG. 1 shows the components of an example virtual or overlay networkincluding a VCN, subnets within the VCN, compute instances deployed onsubnets, VNICs associated with the compute instances, a VR for a VCN,and a set of gateways configured for the VCN. The overlay componentsdepicted in FIG. 1 may be executed or hosted by one or more of thephysical components depicted in FIG. 2 . For example, the computeinstances in a VCN may be executed or hosted by one or more hostmachines depicted in FIG. 2 . For a compute instance hosted by a hostmachine, the VNIC associated with that compute instance is typicallyexecuted by an NVD connected to that host machine (i.e., the VNICfunctionality is provided by the NVD connected to that host machine).The VCN VR function for a VCN is executed by all the NVDs that areconnected to host machines hosting or executing the compute instancesthat are part of that VCN. The gateways associated with a VCN may beexecuted by one or more different types of NVDs. For example, certaingateways may be executed by smartNICs, while others may be executed byone or more host machines or other implementations of NVDs.

As described above, a compute instance in a customer VCN may communicatewith various different endpoints, where the endpoints can be within thesame subnet as the source compute instance, in a different subnet butwithin the same VCN as the source compute instance, or with an endpointthat is outside the VCN of the source compute instance. Thesecommunications are facilitated using VNICs associated with the computeinstances, the VCN VRs, and the gateways associated with the VCNs.

For communications between two compute instances on the same subnet in aVCN, the communication is facilitated using VNICs associated with thesource and destination compute instances. The source and destinationcompute instances may be hosted by the same host machine or by differenthost machines. A packet originating from a source compute instance maybe forwarded from a host machine hosting the source compute instance toan NVD connected to that host machine. On the NVD, the packet isprocessed using a packet processing pipeline, which can includeexecution of the VNIC associated with the source compute instance. Sincethe destination endpoint for the packet is within the same subnet,execution of the VNIC associated with the source compute instanceresults in the packet being forwarded to an NVD executing the VNICassociated with the destination compute instance, which then processesand forwards the packet to the destination compute instance. The VNICsassociated with the source and destination compute instances may beexecuted on the same NVD (e.g., when both the source and destinationcompute instances are hosted by the same host machine) or on differentNVDs (e.g., when the source and destination compute instances are hostedby different host machines connected to different NVDs). The VNICs mayuse routing/forwarding tables stored by the NVD to determine the nexthop for the packet.

For a packet to be communicated from a compute instance in a subnet toan endpoint in a different subnet in the same VCN, the packetoriginating from the source compute instance is communicated from thehost machine hosting the source compute instance to the NVD connected tothat host machine. On the NVD, the packet is processed using a packetprocessing pipeline, which can include execution of one or more VNICs,and the VR associated with the VCN. For example, as part of the packetprocessing pipeline, the NVD executes or invokes functionalitycorresponding to the VNIC (also referred to as executes the VNIC)associated with source compute instance. The functionality performed bythe VNIC may include looking at the VLAN tag on the packet. Since thepacket's destination is outside the subnet, the VCN VR functionality isnext invoked and executed by the NVD. The VCN VR then routes the packetto the NVD executing the VNIC associated with the destination computeinstance. The VNIC associated with the destination compute instance thenprocesses the packet and forwards the packet to the destination computeinstance. The VNICs associated with the source and destination computeinstances may be executed on the same NVD (e.g., when both the sourceand destination compute instances are hosted by the same host machine)or on different NVDs (e.g., when the source and destination computeinstances are hosted by different host machines connected to differentNVDs).

If the destination for the packet is outside the VCN of the sourcecompute instance, then the packet originating from the source computeinstance is communicated from the host machine hosting the sourcecompute instance to the NVD connected to that host machine. The NVDexecutes the VNIC associated with the source compute instance. Since thedestination end point of the packet is outside the VCN, the packet isthen processed by the VCN VR for that VCN. The NVD invokes the VCN VRfunctionality, which may result in the packet being forwarded to an NVDexecuting the appropriate gateway associated with the VCN. For example,if the destination is an endpoint within the customer's on-premisenetwork, then the packet may be forwarded by the VCN VR to the NVDexecuting the DRG gateway configured for the VCN. The VCN VR may beexecuted on the same NVD as the NVD executing the VNIC associated withthe source compute instance or by a different NVD. The gateway may beexecuted by an NVD, which may be a smartNIC, a host machine, or otherNVD implementation. The packet is then processed by the gateway andforwarded to a next hop that facilitates communication of the packet toits intended destination endpoint. For example, in the embodimentdepicted in FIG. 2 , a packet originating from compute instance 268 maybe communicated from host machine 202 to NVD 210 over link 220 (usingNIC 232). On NVD 210, VNIC 276 is invoked since it is the VNICassociated with source compute instance 268. VNIC 276 is configured toexamine the encapsulated information in the packet, and determine a nexthop for forwarding the packet with the goal of facilitatingcommunication of the packet to its intended destination endpoint, andthen forward the packet to the determined next hop.

A compute instance deployed on a VCN can communicate with variousdifferent endpoints. These endpoints may include endpoints that arehosted by CSPI 200 and endpoints outside CSPI 200. Endpoints hosted byCSPI 200 may include instances in the same VCN or other VCNs, which maybe the customer's VCNs, or VCNs not belonging to the customer.

Communications between endpoints hosted by CSPI 200 may be performedover physical network 218. A compute instance may also communicate withendpoints that are not hosted by CSPI 200, or are outside CSPI 200.Examples of these endpoints include endpoints within a customer'son-premise network or data center, or public endpoints accessible over apublic network such as the Internet. Communications with endpointsoutside CSPI 200 may be performed over public networks (e.g., theInternet) (not shown in FIG. 2 ) or private networks (not shown in FIG.2 ) using various communication protocols.

The architecture of CSPI 200 depicted in FIG. 2 is merely an example andis not intended to be limiting. Variations, alternatives, andmodifications are possible in alternative embodiments. For example, insome implementations, CSPI 200 may have more or fewer systems orcomponents than those shown in FIG. 2 , may combine two or more systems,or may have a different configuration or arrangement of systems. Thesystems, subsystems, and other components depicted in FIG. 2 may beimplemented in software (e.g., code, instructions, program) executed byone or more processing units (e.g., processors, cores) of the respectivesystems, using hardware, or combinations thereof. The software may bestored on a non-transitory storage medium (e.g., on a memory device).

FIG. 4 depicts connectivity between a host machine and an NVD forproviding I/O virtualization for supporting multitenancy according tocertain embodiments. As depicted in FIG. 4 , host machine 402 executes ahypervisor 404 that provides a virtualized environment. Host machine 402executes two virtual machine instances, VM1 406 belonging tocustomer/tenant #1 and VM2 408 belonging to customer/tenant #2. Hostmachine 402 comprises a physical NIC 410 that is connected to an NVD 412via link 414. Each of the compute instances is attached to a VNIC thatis executed by NVD 412. In the embodiment in FIG. 4 , VM1 406 isattached to VNIC-VM1 420 and VM2 408 is attached to VNIC-VM2 422.

As shown in FIG. 4 , NIC 410 comprises two logical NICs, logical NIC A416 and logical NIC B 418. Each virtual machine is attached to andconfigured to work with its own logical NIC. For example, VM1 406 isattached to logical NIC A 416 and VM2 408 is attached to logical NIC B418. Even though host machine 402 comprises only one physical NIC 410that is shared by the multiple tenants, due to the logical NICs, eachtenant's virtual machine believes they have their own host machine andNIC.

In certain embodiments, each logical NIC is assigned its own VLAN ID.Thus, a specific VLAN ID is assigned to logical NIC A 416 for Tenant #1and a separate VLAN ID is assigned to logical NIC B 418 for Tenant #2.When a packet is communicated from VM1 406, a tag assigned to Tenant #1is attached to the packet by the hypervisor and the packet is thencommunicated from host machine 402 to NVD 412 over link 414. In asimilar manner, when a packet is communicated from VM2 408, a tagassigned to Tenant #2 is attached to the packet by the hypervisor andthe packet is then communicated from host machine 402 to NVD 412 overlink 414. Accordingly, a packet 424 communicated from host machine 402to NVD 412 has an associated tag 426 that identifies a specific tenantand associated VM. On the NVD, for a packet 424 received from hostmachine 402, the tag 426 associated with the packet is used to determinewhether the packet is to be processed by VNIC-VM1 420 or by VNIC-VM2422. The packet is then processed by the corresponding VNIC. Theconfiguration depicted in FIG. 4 enables each tenant's compute instanceto believe that they own their own host machine and NIC. The setupdepicted in FIG. 4 provides for I/O virtualization for supportingmulti-tenancy.

FIG. 5 depicts a simplified block diagram of a physical network 500according to certain embodiments. The embodiment depicted in FIG. 5 isstructured as a Clos network. A Clos network is a particular type ofnetwork topology designed to provide connection redundancy whilemaintaining high bisection bandwidth and maximum resource utilization. AClos network is a type of non-blocking, multistage or multi-tieredswitching network, where the number of stages or tiers can be two,three, four, five, etc. The embodiment depicted in FIG. 5 is a 3-tierednetwork comprising tiers 1, 2, and 3. The TOR switches 504 representTier-0 switches in the Clos network. One or more NVDs are connected tothe TOR switches. Tier-0 switches are also referred to as edge devicesof the physical network. The Tier-0 switches are connected to Tier-1switches, which are also referred to as leaf switches. In the embodimentdepicted in FIG. 5 , a set of “n” Tier-0 TOR switches are connected to aset of “n” Tier-1 switches and together form a pod. Each Tier-0 switchin a pod is interconnected to all the Tier-1 switches in the pod, butthere is no connectivity of switches between pods. In certainimplementations, two pods are referred to as a block. Each block isserved by or connected to a set of “n” Tier-2 switches (sometimesreferred to as spine switches). There can be several blocks in thephysical network topology. The Tier-2 switches are in turn connected to“n” Tier-3 switches (sometimes referred to as super-spine switches).Communication of packets over physical network 500 is typicallyperformed using one or more Layer-3 communication protocols. Typically,all the layers of the physical network, except for the TORs layer aren-ways redundant thus allowing for high availability. Policies may bespecified for pods and blocks to control the visibility of switches toeach other in the physical network so as to enable scaling of thephysical network.

A feature of a Clos network is that the maximum hop count to reach fromone Tier-0 switch to another Tier-0 switch (or from an NVD connected toa Tier-0-switch to another NVD connected to a Tier-0 switch) is fixed.For example, in a 3-Tiered Clos network at most seven hops are neededfor a packet to reach from one NVD to another NVD, where the source andtarget NVDs are connected to the leaf tier of the Clos network.Likewise, in a 4-tiered Clos network, at most nine hops are needed for apacket to reach from one NVD to another NVD, where the source and targetNVDs are connected to the leaf tier of the Clos network. Thus, a Closnetwork architecture maintains consistent latency throughout thenetwork, which is important for communication within and between datacenters. A Clos topology scales horizontally and is cost effective. Thebandwidth/throughput capacity of the network can be easily increased byadding more switches at the various tiers (e.g., more leaf and spineswitches) and by increasing the number of links between the switches atadjacent tiers.

In certain embodiments, each resource within CSPI is assigned a uniqueidentifier called a Cloud Identifier (CID). This identifier is includedas part of the resource's information and can be used to manage theresource, for example, via a Console or through APIs. An example syntaxfor a CID is:

-   -   ocid1.<RESOURCE TYPE>.<REALM>.[REGION][.FUTURE USE].<UNIQUE ID>        where,        ocid1: The literal string indicating the version of the CID;        resource type: The type of resource (for example, instance,        volume, VCN, subnet, user, group, and so on);        realm: The realm the resource is in. Example values are “c1” for        the commercial realm, “c2” for the Government Cloud realm, or        “c3” for the Federal Government Cloud realm, etc. Each realm may        have its own domain name;        region: The region the resource is in. If the region is not        applicable to the resource, this part might be blank;        future use: Reserved for future use.        unique ID: The unique portion of the ID. The format may vary        depending on the type of resource or service.

FIG. 6 depicts a block diagram of a cloud infrastructure 600incorporating a CLOS network arrangement, according to certainembodiments. The cloud infrastructure 600 includes a plurality of racks(e.g., rack 1 610 . . . rack M, 620). Each rack includes a plurality ofhost machines (also referred to herein as hosts). For instance, rack 1610 includes a plurality of hosts (e.g., K host machines) host 1-A, 612to host 1-K, 614, and rack M includes K host machines i.e., Host M-A,622 to Host M-K, 624. It is appreciated that the illustration of FIG. 6(i.e., each rack including the same number of host machines e.g., K hostmachines) is intended to be illustrative and non-limiting. For instance,rack M, 620 may have a higher or lower number of host machines ascompared to the number of host machines included in rack 1, 610.

Each host machine includes a plurality of graphical processing units(GPUs). For example, as shown in FIG. 6 , Host machine 1-A 612 includesN GPUs e.g., GPU 1, 613. Moreover, it is appreciated that theillustration in FIG. 6 (of having each host machine including the samenumber of GPUs, i.e., N GPUs), is intended to be illustrative andnon-limiting i.e., each host machine can include a different number ofGPUs. Each rack includes a top of rack (TOR) switch that iscommunicatively coupled with the GPUs hosted on the host machines. Forexample, rack 1 610 includes a TOR switch (i.e., TOR 1) 616 that iscommunicatively coupled to Host 1-A, 612 and Host 1-K, 614, and rack M620 includes a TOR switch (i.e., TOR M) 626 that is communicativelycoupled to Host M-A, 622 and Host M-K, 624. It is appreciated that theTOR switches depicted in FIG. 6 (i.e., TOR 1 616, and TOR M 626), eachinclude N ports that are used to communicatively couple the TOR switchto the N GPUs hosted on each host machine included in the rack. Thecoupling of TOR switches to the GPUs as depicted in FIG. 6 is intendedto be illustrative and non-limiting. For instance, in some embodiments,the TOR switch may have a plurality of ports, each of which correspondsto a GPU on each host machine i.e., a GPU on a host machine may beconnected to a unique port of the TOR via a communication link.Moreover, traffic received by a network device (e.g., TOR 1 616) ischaracterized herein as traffic received on a particular incomingport-link of the network device. For example, when GPU 1 613 of Host 1-A612 transmits a data packet to TOR 1 616 (using link 617), the datapacket is received on port 619 of the TOR 1 switch. TOR 1 616characterizes this data packet as information received on a firstincoming port-link of the TOR. It is appreciated that a similar notioncan be applied to all outgoing port-links of the TOR.

The TOR switches from each rack are communicatively coupled to aplurality of spine switches e.g., spine switch 1, 630 and spine switch P640. As shown in FIG. 6 , TOR 1, 616 is connected to spine switch 1 630via two links, and to spine switch P 640 via another two links,respectively. Information transmitted from a particular TOR switch to aspine switch is referred to herein as communication conducted viauplinks, whereas information transmitted from a spine switch to a TORswitch is referred to herein as communication conducted via downlinks.According to some embodiments, the TOR switches and the spine switchesare connected in a CLOS network arrangement (e.g., a multi-stageswitching network), where each TOR switch forms a ‘leaf’ node in theCLOS network.

According to some embodiments, the GPUs included in the host machinesexecute tasks related to machine learning. In such a setting, a singletask may be performed/spread across a large number of GPUs (e.g., 64)that in turn could be spread across multiple host machines and acrossmultiple racks. Since all these GPUs are working on the same task (i.e.,a workload), they all need to communicate with each other in a timesynchronized manner. Furthermore, at any given time instant, the GPUsare either in one of a compute mode or a communication mode i.e., GPUstalk to one another at roughly the same time instant. The speed of theworkload is determined by the speed of the slowest GPU.

Typically, to route packets from a source GPU (e.g., GPU 1, 613 of Host1-A 612) to a destination GPU (e.g., GPU 1, 623 of Host M-A 622), equalcost multipath (ECMP) routing is utilized. In ECMP routing, when thereare multiple equal cost paths available for routing traffic from asender to a receiver, a selection technique is used to select aparticular path. Accordingly, at a network device (e.g., a TOR switch ora spine switch) receiving the traffic, a selection algorithm is used toselect an outgoing link to be used for forwarding the traffic from thenetwork device on a next hop to another network device. Such an outgoinglink selection occurs at each network device in the path from the senderto the receiver. A hash-based selection algorithm is a widely used ECMPselection technique, where the hash may be based upon a 4-tuple of apacket (e.g., source port, destination port, source IP, destination IP).

ECMP routing is a flow aware routing technique, where each flow (i.e., astream of data packets) is hashed to a particular path for the durationof the flow. Thus, packets in a flow are forwarded from a network deviceusing a particular outgoing port/link. This is typically done in orderto ensure that packets in a flow arrive in order i.e., no re-ordering ofpackets is required. However, ECMP routing is bandwidth (or throughput)unaware. In other words, the TOR and spine switches perform statisticalflow-aware (throughput unaware) ECMP load balancing of flows on parallellinks.

In standard ECMP routing (i.e., only flow aware routing), a problem isthat flows received by a network device over two separate incoming linksmay get hashed to the same outgoing link, thereby resulting in a flowcollision. For instance, consider a situation where the two flows arecoming in over two separate incoming 100G links, and each of the flowsgets hashed to the same 100G outgoing link. Such a situation results ina congestion (i.e., flow collision) and results in packets beingdropped, since the incoming bandwidth is 200G, but outgoing bandwidth is100G. For example, FIG. 7 described below, illustrates an exemplaryscenario of a flow collision 700.

As shown in FIG. 7 , there are two flows: flow 1 710 which is directedfrom a first GPU of the host machine host 1-A, 612 to the TOR switch 616(depicted by solid line), and flow 2 720, which is directed from anotherGPU on the same host machine 612 to the TOR switch 616 (depicted bydashed line). Note that the two flows are directed to the TOR switch 616on separate links i.e., separate incoming port-links of the TOR. It isassumed that all links depicted in FIG. 7 have a capacity (i.e.,bandwidth) of 100G. In the case where the TOR switch 616 performs ECMProuting algorithm, it is possible that the two flows get hashed to usethe same outgoing port-link of the TOR e.g., port of the TOR connectedto link 730, which connects the TOR switch 616 to spine switch 630. Inthis case, there is a collision between the two flows (represented by‘X’ mark), which results in packets being dropped.

Such a collision scenario is generally problematic for all types oftraffic irrespective of the protocol. For example, TCP is intelligent inthat when a packet gets dropped and the sender does not get anacknowledgment for that dropped packet, the packet is re-transmitted.However, the situation is worsened for remote direct memory access(RDMA) type traffic. RDMA networks do not use TCP for a variety ofreasons (e.g., TCP has a complex logic that does not lend well to lowlatency and high performance). RDMA networks use protocols such as RDMAover Infiniband or RDMA over converged Ethernet (RoCE). In RoCE, thereis a congestion control algorithm, wherein when a sender identifies theoccurrence of a congestion or dropped packets, the sender slows down thetransmission of packets. For a dropped packet, not only the droppedpackets, but also several packets around the dropped packet areretransmitted that further eats away the available bandwidth and resultsin poor performance.

Described below are techniques to overcome the above described flowcollision problem. It is appreciated that the flow collision problemaffects traffic from CPUs and GPUs. However, the flow collision issue isa much bigger problem for GPUs due to the stringent time synchronizationrequirements. Furthermore, it is to be appreciated that the standardECMP routing mechanism will incur the flow collisions scenariosirrespective of whether the network is over or under subscribed due toits inherent property of routing information in a statistical bandwidthunaware manner. A network with no oversubscription is one wherebandwidth of incoming links to a device (e.g., TOR, spine switch) is thesame as bandwidth of outgoing links. Note that if all links have thesame bandwidth capacity, then the number of incoming links is the sameas the number of outgoing links.

According to some embodiments, techniques to overcome the above statedflow collision problem include a GPU based policy routing mechanism(also referred to herein as a GPU-based Traffic Engineering mechanism),and a modified ECMP routing mechanism. Each of these techniques isdescribed in further detail below.

FIG. 8 depicts a policy based routing mechanism implemented in thenetwork devices of the cloud infrastructure of FIG. 6 , according tocertain embodiments. Specifically, the cloud infrastructure 800 includesa plurality of racks e.g., rack 1 810 to rack M 820. Each rack includesa host machine including a plurality of GPUs. For instance, rack 1 810includes a host machine i.e., Host 1-A 812 and rack M 820 includes ahost machine i.e., Host M-A 822. Each rack includes a TOR switch e.g.,rack 1 810 includes TOR 1 switch 814 and rack M 820 includes TOR Mswitch 824. The host machine in each rack is communicatively coupled tothe respective TOR switch in the rack. The TOR switches i.e., TOR switch1, 814 and TOR switch M 824 are in turn communicatively coupled to thespine switches i.e. spine switch 830 and spine switch 840. To describethe policy based routing and for sake of illustration, the cloudinfrastructure 800 is depicted as including a single host machine perrack. However, it is appreciated that each rack in the infrastructuremay have more than one host machine.

According to some embodiments, data packets from a sender to a receiverare routed in the network on a hop-by-hop basis. A routing policy isconfigured at each network device that ties an incoming port-link to anoutgoing port-link. The network device could be a TOR switch or thespine switch. Referring to FIG. 8 , there are depicted two flows: flow 1from GPU 1 on host machine 812 whose intended destination is GPU 1 onhost machine 822, and flow 2 from GPU N on host machine 812 whoseintended destination is GPU N on host machine 822. The network devicesi.e., TOR 1 814, spine 1 830, TOR M 824, and spine P 840 are configuredto tie (or match) an incoming port-link to an outgoing port-link. Amatching of the incoming port-links to outgoing port-links is maintained(e.g., in a policy table) at each network device.

Referring to FIG. 8 , it can be observed that with regard to flow 1(i.e., flow depicted by solid lines), that when TOR 1 814 receives apacket on link 850, the TOR is configured to forward the received packeton outgoing link 855. Similarly, when the spine switch 830 receives thepacket via link 855, it is configured to forward the packet on outgoinglink 860. Eventually, when TOR M 824 receives the packet on link 860, itis configured to forward the packet on outgoing link 865 in order totransmit the packet to its intended destination i.e., GPU 1 on hostmachine 822. Similarly, with regard to flow 2 (i.e., flow depicted bydashed lines), when TOR 1 814 receives a packet on link 870, TOR 1 isconfigured to forward the received packet on outgoing link 875 to spineP 840. When the spine switch 840 receives the packet via link 875, it isconfigured to forward the packet on outgoing link 880. Eventually, whenTOR M 824 receives the packet on link 880, it is configured to forwardthe packet on outgoing link 885 in order to transmit the packet to itsintended destination i.e., GPU N on host machine 822.

In this manner, according to GPU policy based routing mechanism, eachnetwork device is configured to tie an incoming port/link to an outgoingport/link in order to avoid collisions. For example, considering thefirst hop flows of flow 1 and flow 2, the TOR 1 814 receives a firstdata packet (corresponding to flow 1) on link 850, and receives a seconddata packet (corresponding to flow 2) on link 870. As TOR 1 814, isconfigured to forward data packets received on incoming link/port 850 tooutgoing link/port 855, and to forward data packets received on incominglink/port 870 to outgoing link/port 875, it is ensured that the firstand second data packets will not collide. It is appreciated that at eachnetwork device within the cloud infrastructure, there is a 1-1correspondence between an incoming port-link and an outgoing port-linki.e., a mapping between the incoming port-link and an outgoing port-linkis performed independent of the flows and/or the protocols executed bythe flows. Furthermore, in the event that an outgoing link of aparticular network device fails, according to some embodiments, thenetwork device is configured to switch its routing policy from the GPUpolicy based routing to a standard ECMP routing to obtain a newavailable output link (from various available output links) and send theflow down that new output link. It is noted that in this case, one mayincur flow collision resulting in congestion.

Turning now to FIG. 9 , there is depicted a block diagram of a cloudinfrastructure 900 illustrating different types of connections,according to certain embodiments. The infrastructure 900 includes aplurality of racks e.g., rack 1 910, rack D 920, and rack M, 930. Racks910 and 930 include a plurality of host machines. For instance, rack 1910 includes a plurality of hosts (e.g., K host machines) Host 1-A, 912to Host 1-K, 914, and rack M includes K host machines i.e., Host M-A,932 to Host M-K, 934. Rack D 920 includes one or more host machines 922,each of which include a plurality of CPUs i.e., the host machine 922 isa non-GPU host machine. Each of the racks 910, 920, and 930 include aTOR switch i.e., TOR 1, 916, TOR D 926, and TOR M 936, respectively thatare communicatively coupled to the host machines in the respectiveracks. Further, the TOR switches 916, 926, and 936 are communicativelycoupled to a plurality of spine switches i.e., spine switches 940 and950.

As shown in FIG. 9 , a first connection (i.e., connection 1 depicted bydashed lines) exists from a GPU host (i.e., Host 1-A 912) to another GPUhost (i.e., Host M-A 932), and a second connection (i.e., connection 2depicted by dotted lines) exists from a GPU host (i.e., Host 1-K 914) toa non-GPU host (i.e., Host D 922). With regard to connection 1, datapackets associated with the flow are routed on a hop-by-hop basis byconfiguring each intermediate network device based on the GPU basedpolicy routing mechanism as described previously in FIG. 8 .Specifically, the data packets of connection 1 are routed along thedashed links depicted in FIG. 9 . i.e., from host 1-A to TOR 1, from TOR1 to spine switch 1, from spine switch 1 to TOR M, and eventually fromTOR M to host M-A. Each of the network devices is configured to tie anincoming link-port to an outgoing link-port of the network device.

In contrast, connection 2 is from a GPU based host (i.e., Host 1-K 914)to a non-GPU based host (i.e., Host D 922). In this case, TOR 1 916, isconfigured to tie an incoming link-port i.e., port and link (971) onwhich it receives data packets from a GPU based host to an outgoinglink-port i.e., an output port and link 972 connected to the outputport. Thus, TOR 1 forwards the data packets to spine switch 1 940 usingthe outgoing link 972. As the data packets are destined for a non-GPUbased host, spine switch 1 940 does not utilize the policy based routingmechanism to forward the packets to TOR D. Rather, spine switch 1 940utilizes the ECMP routing mechanism to select one of the available links980 to forward the packets to TOR D, which then forwards the datapackets to Host D 922.

In some embodiments, the flow collision described previously withreference to FIG. 7 is avoided by network devices of the cloudinfrastructures described herein by implementing a modified version ofECMP routing. In this case, the ECMP hash algorithm is modified suchthat, traffic coming over a particular incoming port-link of a networkdevice is hashed (and directed) to a same outgoing port-link of thenetwork device. Specifically, each network device implements a modifiedECMP algorithm to determine an output port-link to be used forforwarding the packet, wherein per the modified ECMP algorithm, anypacket received over a particular incoming port-link always hashes tothe same outgoing port-link. For example, consider the case where afirst packet and a second packet are received on a first incomingport-link of a network device, whereas a third packet and a fourthpacket are received on a second incoming port-link of the networkdevice. In such a situation, the network device is configured toimplement the modified ECMP algorithm where the network device transmitsthe first packet and the second packet on a first outgoing port-link ofthe network device, and transmits the third packet and the fourth packeton a second outgoing port-link of the network device, where the firstincoming port-link of the network device is different than the secondincoming port-link of the network device, and the first outgoingport-link of the network device is different than the second outgoingport-link of the network device. In certain implementations, theinformation stored in a forwarding information database (e.g.,forwarding tables, ECMP tables, etc.,) can be modified to enable theabove stated functionality.

Turning now to FIG. 10 , there is illustrated an exemplary configurationof a rack 1000, according to certain embodiments. As shown in FIG. 10 ,the rack 1000 includes two host machines i.e., host machine 1010 andhost machine 1020. It is appreciated that although rack 1000 is depictedas including two host machines, the rack 1000 may include more number ofhost machines. Each host machine includes a plurality of GPUs and aplurality of CPUs. For example, the host machine 1010 includes aplurality of CPUs 1012 and a plurality of GPUs 1014, whereas the hostmachine 1020 includes a plurality of CPUs 1022 and a plurality of GPUs1024.

The host machines are communicatively coupled to different networkfabrics via different TOR switches. For instance, host machines 1010 and1020 are communicatively coupled to a network fabric (referred to hereinas a front-end network of the rack 1000) via a TOR switch i.e., TOR 1switch 1050. The front-end network may correspond to an externalnetwork. More specifically, the host machine 1010 is connected to thefront-end network, via a network interface card (NIC) 1030 and a networkvirtualization device (NVD) 1035, which is coupled to the TOR 1 switch1050. The host machine 1020 is connected to the front-end network via aNIC 1040 and a NVD 1045, which is coupled to the TOR 1 switch 1050.Thus, by some embodiments, the CPUs of each host machine may communicatewith the front-end network via the NIC, NVD, and TOR switch. Forexample, CPUs 1012 of host machine 1010 may communicate with thefront-end network via NIC 1030, NVD 1035, and TOR 1 switch 1050.

The host machines 1010 and 1020 are connected to a quality of service(QoS) enabled backend network on the other side. The (QoS) enabledbackend network is referred to herein as a backend network thatcorresponds to a GPU cluster network as shown in FIG. 6 . Host machine1010 is connected via another NIC 1065 to a TOR 2 switch 1060 whichcommunicatively couples the host machine 1010 to the backend network.Similarly, host machine 1020 is connected via NIC 1080 to the TOR 2switch 1060, which communicatively couples the host machine 1020 to thebackend network. Thus, the plurality of GPUs of each host machine maycommunicate with the back-end network via a NIC and a TOR switch In thismanner, the plurality of CPUs utilize a separate set of NICs (ascompared to the set of NICs utilized by GPUs) in order to communicatewith the front-end and back-end networks, respectively.

FIG. 11A depicts an exemplary flowchart 1100 depicting steps performedby a network device in routing a packet, according to certainembodiments. The processing depicted in FIG. 11A may be implemented insoftware (e.g., code, instructions, program) executed by one or moreprocessing units (e.g., processors, cores) of the respective systems,hardware, or combinations thereof. The software may be stored on anon-transitory storage medium (e.g., on a memory device). The methodpresented in FIG. 11A and described below is intended to be illustrativeand non-limiting. Although FIG. 11A depicts the various processing stepsoccurring in a particular sequence or order, this is not intended to belimiting. In certain alternative embodiments, the steps may be performedin some different order or some steps may also be performed in parallel.

The process commences in step 1105 where a network device receives adata packet transmitted by a graphical processing unit (GPU) of a hostmachine. In step 1110, the network device determines an incomingport/link that the packet was received on. In step 1115, the networkdevice identifies an outgoing port/link corresponding to the incomingport/link (on which the packet was received) based on a policy routinginformation. According to some embodiments, the policy routinginformation corresponds to a pre-configured GPU routing table for thenetwork device that ties each incoming port-link of the network deviceto a unique outgoing link-port of the network device.

The process then moves to step 1120, where a query is performed todetermine whether the outgoing port-link is in a functioning state e.g.,the outgoing link is active. If the response to the query is affirmative(i.e., the link is active), then the process moves to step 1125, else ifthe response to the query is negative (i.e., the link is in a failedstate/inactive state), then the process moves to step 1130. In step1125, the network device utilizes the outgoing port-link (identified instep 1115) to forward the received data packet to another networkdevice. In step 1130, the network device obtains flow information of thedata packet e.g., the flow information may correspond to a 4-tupleassociated with the packet (i.e., source port, destination port, sourceIP address, destination IP address). Based on the obtained flowinformation, the network device utilizes ECMP routing to identify a newoutgoing port-link i.e., an available outgoing port-link. The processthen moves to step 1135 where the network device utilizes the newlyobtained outgoing port-link to forward the data packet received in step1105.

FIG. 11B depicts another exemplary flowchart 1150 depicting stepsperformed by a network device in routing a packet, according to certainembodiments. The processing depicted in FIG. 11B may be implemented insoftware (e.g., code, instructions, program) executed by one or moreprocessing units (e.g., processors, cores) of the respective systems,hardware, or combinations thereof. The software may be stored on anon-transitory storage medium (e.g., on a memory device). The methodpresented in FIG. 11B and described below is intended to be illustrativeand non-limiting. Although FIG. 11B depicts the various processing stepsoccurring in a particular sequence or order, this is not intended to belimiting. In certain alternative embodiments, the steps may be performedin some different order or some steps may also be performed in parallel.

The process commences in step 1155, where a network device receives adata packet transmitted by a graphical processing unit (GPU) of a hostmachine. In step 1160, the network device determines flow information ofthe received packet. In some implementations, the flow information maycorrespond to 4-tuple associated with the packet (i.e., source port,destination port, source IP address, destination IP address). In step1165, the network device computes an outgoing port-link by implementinga modified version of the ECMP routing. Per the modified ECMP algorithm,any packet received over a particular incoming port-link is alwayshashed to be transmitted on the same outgoing port-link.

The process then moves to step 1170, where a query is performed todetermine whether the outgoing port-link (determined in step 1165) is ina functioning state e.g., the outgoing link is active. If the responseto the query is affirmative (i.e., the link is active), then the processmoves to step 1175, else if the response to the query is negative (i.e.,the link is in a failed state/inactive state), then the process moves tostep 1180. In step 1175, the network device utilizes the outgoingport-link (identified in step 1165) to forward the received data packetto another network device. In the event that the identified outgoingport-link (of step 1165) is determined to be in an inactive state, thenthe process moves to step 1180. In step 1180, the network deviceimplements ECMP routing (i.e., standard ECMP routing) to identify a newoutgoing port-link. The process then moves to step 1185 where thenetwork device utilizes the newly computed outgoing port-link to forwardthe data packet received in step 1155.

It is noted that the above described techniques of routing data packetsoriginating from a GPU of a host machine leads to an increase inthroughput by 20% for smaller clusters, and 70% for larger clusters(i.e., a 3× improvement over standard ECMP routing algorithm). ExampleCloud Infrastructure embodiment

As noted above, infrastructure as a service (IaaS) is one particulartype of cloud computing. IaaS can be configured to provide virtualizedcomputing resources over a public network (e.g., the Internet). In anIaaS model, a cloud computing provider can host the infrastructurecomponents (e.g., servers, storage devices, network nodes (e.g.,hardware), deployment software, platform virtualization (e.g., ahypervisor layer), or the like). In some cases, an IaaS provider mayalso supply a variety of services to accompany those infrastructurecomponents (e.g., billing, monitoring, logging, security, load balancingand clustering, etc.). Thus, as these services may be policy-driven,IaaS users may be able to implement policies to drive load balancing tomaintain application availability and performance.

In some instances, IaaS customers may access resources and servicesthrough a wide area network (WAN), such as the Internet, and can use thecloud provider's services to install the remaining elements of anapplication stack. For example, the user can log in to the IaaS platformto create virtual machines (VMs), install operating systems (OSs) oneach VM, deploy middleware such as databases, create storage buckets forworkloads and backups, and even install enterprise software into thatVM. Customers can then use the provider's services to perform variousfunctions, including balancing network traffic, troubleshootingapplication issues, monitoring performance, managing disaster recovery,etc.

In most cases, a cloud computing model will require the participation ofa cloud provider. The cloud provider may, but need not be, a third-partyservice that specializes in providing (e.g., offering, renting, selling)IaaS. An entity might also opt to deploy a private cloud, becoming itsown provider of infrastructure services.

In some examples, IaaS deployment is the process of putting a newapplication, or a new version of an application, onto a preparedapplication server or the like. It may also include the process ofpreparing the server (e.g., installing libraries, daemons, etc.). Thisis often managed by the cloud provider, below the hypervisor layer(e.g., the servers, storage, network hardware, and virtualization).Thus, the customer may be responsible for handling (OS), middleware,and/or application deployment (e.g., on self-service virtual machines(e.g., that can be spun up on demand) or the like.

In some examples, IaaS provisioning may refer to acquiring computers orvirtual hosts for use, and even installing needed libraries or serviceson them. In most cases, deployment does not include provisioning, andthe provisioning may need to be performed first.

In some cases, there are two different challenges for IaaS provisioning.First, there is the initial challenge of provisioning the initial set ofinfrastructure before anything is running. Second, there is thechallenge of evolving the existing infrastructure (e.g., adding newservices, changing services, removing services, etc.) once everythinghas been provisioned. In some cases, these two challenges may beaddressed by enabling the configuration of the infrastructure to bedefined declaratively. In other words, the infrastructure (e.g., whatcomponents are needed and how they interact) can be defined by one ormore configuration files. Thus, the overall topology of theinfrastructure (e.g., what resources depend on which, and how they eachwork together) can be described declaratively. In some instances, oncethe topology is defined, a workflow can be generated that creates and/ormanages the different components described in the configuration files.

In some examples, an infrastructure may have many interconnectedelements. For example, there may be one or more virtual private clouds(VPCs) (e.g., a potentially on-demand pool of configurable and/or sharedcomputing resources), also known as a core network. In some examples,there may also be one or more security group rules provisioned to definehow the security of the network will be set up and one or more virtualmachines (VMs). Other infrastructure elements may also be provisioned,such as a load balancer, a database, or the like. As more and moreinfrastructure elements are desired and/or added, the infrastructure mayincrementally evolve.

In some instances, continuous deployment techniques may be employed toenable deployment of infrastructure code across various virtualcomputing environments. Additionally, the described techniques canenable infrastructure management within these environments. In someexamples, service teams can write code that is desired to be deployed toone or more, but often many, different production environments (e.g.,across various different geographic locations, sometimes spanning theentire world). However, in some examples, the infrastructure on whichthe code will be deployed must first be set up. In some instances, theprovisioning can be done manually, a provisioning tool may be utilizedto provision the resources, and/or deployment tools may be utilized todeploy the code once the infrastructure is provisioned.

FIG. 12 is a block diagram 1200 illustrating an example pattern of anIaaS architecture, according to at least one embodiment. Serviceoperators 1202 can be communicatively coupled to a secure host tenancy1204 that can include a virtual cloud network (VCN) 1206 and a securehost subnet 1208. In some examples, the service operators 1202 may beusing one or more client computing devices, which may be portablehandheld devices (e.g., an iPhone®, cellular telephone, an iPad®,computing tablet, a personal digital assistant (PDA)) or wearabledevices (e.g., a Google Glass® head mounted display), running softwaresuch as Microsoft Windows Mobile®, and/or a variety of mobile operatingsystems such as iOS, Windows Phone, Android, BlackBerry 8, Palm OS, andthe like, and being Internet, e-mail, short message service (SMS),Blackberry®, or other communication protocol enabled. Alternatively, theclient computing devices can be general purpose personal computersincluding, by way of example, personal computers and/or laptop computersrunning various versions of Microsoft Windows®, Apple Macintosh®, and/orLinux operating systems. The client computing devices can be workstationcomputers running any of a variety of commercially-available UNIX® orUNIX-like operating systems, including without limitation the variety ofGNU/Linux operating systems, such as for example, Google Chrome OS.Alternatively, or in addition, client computing devices may be any otherelectronic device, such as a thin-client computer, an Internet-enabledgaming system (e.g., a Microsoft Xbox gaming console with or without aKinect® gesture input device), and/or a personal messaging device,capable of communicating over a network that can access the VCN 1206and/or the Internet.

The VCN 1206 can include a local peering gateway (LPG) 1210 that can becommunicatively coupled to a secure shell (SSH) VCN 1212 via an LPG 1210contained in the SSH VCN 1212. The SSH VCN 1212 can include an SSHsubnet 1214, and the SSH VCN 1212 can be communicatively coupled to acontrol plane VCN 1216 via the LPG 1210 contained in the control planeVCN 1216. Also, the SSH VCN 1212 can be communicatively coupled to adata plane VCN 1218 via an LPG 1210. The control plane VCN 1216 and thedata plane VCN 1218 can be contained in a service tenancy 1219 that canbe owned and/or operated by the IaaS provider.

The control plane VCN 1216 can include a control plane demilitarizedzone (DMZ) tier 1220 that acts as a perimeter network (e.g., portions ofa corporate network between the corporate intranet and externalnetworks). The DMZ-based servers may have restricted responsibilitiesand help keep security breaches contained. Additionally, the DMZ tier1220 can include one or more load balancer (LB) subnet(s) 1222, acontrol plane app tier 1224 that can include app subnet(s) 1226, acontrol plane data tier 1228 that can include database (DB) subnet(s)1230 (e.g., frontend DB subnet(s) and/or backend DB subnet(s)). The LBsubnet(s) 1222 contained in the control plane DMZ tier 1220 can becommunicatively coupled to the app subnet(s) 1226 contained in thecontrol plane app tier 1224 and an Internet gateway 1234 that can becontained in the control plane VCN 1216, and the app subnet(s) 1226 canbe communicatively coupled to the DB subnet(s) 1230 contained in thecontrol plane data tier 1228 and a service gateway 1236 and a networkaddress translation (NAT) gateway 1238. The control plane VCN 1216 caninclude the service gateway 1236 and the NAT gateway 1238.

The control plane VCN 1216 can include a data plane mirror app tier 1240that can include app subnet(s) 1226. The app subnet(s) 1226 contained inthe data plane mirror app tier 1240 can include a virtual networkinterface controller (VNIC) 1242 that can execute a compute instance1244. The compute instance 1244 can communicatively couple the appsubnet(s) 1226 of the data plane mirror app tier 1240 to app subnet(s)1226 that can be contained in a data plane app tier 1246.

The data plane VCN 1218 can include the data plane app tier 1246, a dataplane DMZ tier 1248, and a data plane data tier 1250. The data plane DMZtier 1248 can include LB subnet(s) 1222 that can be communicativelycoupled to the app subnet(s) 1226 of the data plane app tier 1246 andthe Internet gateway 1234 of the data plane VCN 1218. The app subnet(s)1226 can be communicatively coupled to the service gateway 1236 of thedata plane VCN 1218 and the NAT gateway 1238 of the data plane VCN 1218.The data plane data tier 1250 can also include the DB subnet(s) 1230that can be communicatively coupled to the app subnet(s) 1226 of thedata plane app tier 1246.

The Internet gateway 1234 of the control plane VCN 1216 and of the dataplane VCN 1218 can be communicatively coupled to a metadata managementservice 1252 that can be communicatively coupled to public Internet1254. Public Internet 1254 can be communicatively coupled to the NATgateway 1238 of the control plane VCN 1216 and of the data plane VCN1218. The service gateway 1236 of the control plane VCN 1216 and of thedata plane VCN 1218 can be communicatively couple to cloud services1256.

In some examples, the service gateway 1236 of the control plane VCN 1216or of the data plane VCN 1218 can make application programming interface(API) calls to cloud services 1256 without going through public Internet1254. The API calls to cloud services 1256 from the service gateway 1236can be one-way: the service gateway 1236 can make API calls to cloudservices 1256, and cloud services 1256 can send requested data to theservice gateway 1236. But, cloud services 1256 may not initiate APIcalls to the service gateway 1236.

In some examples, the secure host tenancy 1204 can be directly connectedto the service tenancy 1219, which may be otherwise isolated. The securehost subnet 1208 can communicate with the SSH subnet 1214 through an LPG1210 that may enable two-way communication over an otherwise isolatedsystem. Connecting the secure host subnet 1208 to the SSH subnet 1214may give the secure host subnet 1208 access to other entities within theservice tenancy 1219.

The control plane VCN 1216 may allow users of the service tenancy 1219to set up or otherwise provision desired resources. Desired resourcesprovisioned in the control plane VCN 1216 may be deployed or otherwiseused in the data plane VCN 1218. In some examples, the control plane VCN1216 can be isolated from the data plane VCN 1218, and the data planemirror app tier 1240 of the control plane VCN 1216 can communicate withthe data plane app tier 1246 of the data plane VCN 1218 via VNICs 1242that can be contained in the data plane mirror app tier 1240 and thedata plane app tier 1246.

In some examples, users of the system, or customers, can make requests,for example create, read, update, or delete (CRUD) operations, throughpublic Internet 1254 that can communicate the requests to the metadatamanagement service 1252. The metadata management service 1252 cancommunicate the request to the control plane VCN 1216 through theInternet gateway 1234. The request can be received by the LB subnet(s)1222 contained in the control plane DMZ tier 1220. The LB subnet(s) 1222may determine that the request is valid, and in response to thisdetermination, the LB subnet(s) 1222 can transmit the request to appsubnet(s) 1226 contained in the control plane app tier 1224. If therequest is validated and requires a call to public Internet 1254, thecall to public Internet 1254 may be transmitted to the NAT gateway 1238that can make the call to public Internet 1254. Memory that may bedesired to be stored by the request can be stored in the DB subnet(s)1230.

In some examples, the data plane mirror app tier 1240 can facilitatedirect communication between the control plane VCN 1216 and the dataplane VCN 1218. For example, changes, updates, or other suitablemodifications to configuration may be desired to be applied to theresources contained in the data plane VCN 1218. Via a VNIC 1242, thecontrol plane VCN 1216 can directly communicate with, and can therebyexecute the changes, updates, or other suitable modifications toconfiguration to, resources contained in the data plane VCN 1218.

In some embodiments, the control plane VCN 1216 and the data plane VCN1218 can be contained in the service tenancy 1219. In this case, theuser, or the customer, of the system may not own or operate either thecontrol plane VCN 1216 or the data plane VCN 1218. Instead, the IaaSprovider may own or operate the control plane VCN 1216 and the dataplane VCN 1218, both of which may be contained in the service tenancy1219. This embodiment can enable isolation of networks that may preventusers or customers from interacting with other users', or othercustomers', resources. Also, this embodiment may allow users orcustomers of the system to store databases privately without needing torely on public Internet 1254, which may not have a desired level ofsecurity, for storage.

In other embodiments, the LB subnet(s) 1222 contained in the controlplane VCN 1216 can be configured to receive a signal from the servicegateway 1236. In this embodiment, the control plane VCN 1216 and thedata plane VCN 1218 may be configured to be called by a customer of theIaaS provider without calling public Internet 1254. Customers of theIaaS provider may desire this embodiment since database(s) that thecustomers use may be controlled by the IaaS provider and may be storedon the service tenancy 1219, which may be isolated from public Internet1254.

FIG. 13 is a block diagram 1300 illustrating another example pattern ofan IaaS architecture, according to at least one embodiment. Serviceoperators 1302 (e.g. service operators 1202 of FIG. 12 ) can becommunicatively coupled to a secure host tenancy 1304 (e.g. the securehost tenancy 1204 of FIG. 12 ) that can include a virtual cloud network(VCN) 1306 (e.g. the VCN 1206 of FIG. 12 ) and a secure host subnet 1308(e.g. the secure host subnet 1208 of FIG. 12 ). The VCN 1306 can includea local peering gateway (LPG) 1310 (e.g. the LPG 1210 of FIG. 12 ) thatcan be communicatively coupled to a secure shell (SSH) VCN 1312 (e.g.the SSH VCN 1212 of FIG. 12 ) via an LPG 1310 contained in the SSH VCN1312. The SSH VCN 1312 can include an SSH subnet 1314 (e.g. the SSHsubnet 1214 of FIG. 12 ), and the SSH VCN 1312 can be communicativelycoupled to a control plane VCN 1316 (e.g. the control plane VCN 1216 ofFIG. 12 ) via an LPG 1310 contained in the control plane VCN 1316. Thecontrol plane VCN 1316 can be contained in a service tenancy 1319 (e.g.the service tenancy 1219 of FIG. 12 ), and the data plane VCN 1318 (e.g.the data plane VCN 1218 of FIG. 12 ) can be contained in a customertenancy 1321 that may be owned or operated by users, or customers, ofthe system.

The control plane VCN 1316 can include a control plane DMZ tier 1320(e.g. the control plane DMZ tier 1220 of FIG. 12 ) that can include LBsubnet(s) 1322 (e.g. LB subnet(s) 1222 of FIG. 12 ), a control plane apptier 1324 (e.g. the control plane app tier 1224 of FIG. 12 ) that caninclude app subnet(s) 1326 (e.g. app subnet(s) 1226 of FIG. 12 ), acontrol plane data tier 1328 (e.g. the control plane data tier 1228 ofFIG. 12 ) that can include database (DB) subnet(s) 1330 (e.g. similar toDB subnet(s) 1230 of FIG. 12 ). The LB subnet(s) 1322 contained in thecontrol plane DMZ tier 1320 can be communicatively coupled to the appsubnet(s) 1326 contained in the control plane app tier 1324 and anInternet gateway 1334 (e.g. the Internet gateway 1234 of FIG. 12 ) thatcan be contained in the control plane VCN 1316, and the app subnet(s)1326 can be communicatively coupled to the DB subnet(s) 1330 containedin the control plane data tier 1328 and a service gateway 1336 (e.g. theservice gateway of FIG. 12 ) and a network address translation (NAT)gateway 1338 (e.g. the NAT gateway 1238 of FIG. 12 ). The control planeVCN 1316 can include the service gateway 1336 and the NAT gateway 1338.

The control plane VCN 1316 can include a data plane mirror app tier 1340(e.g. the data plane mirror app tier 1240 of FIG. 12 ) that can includeapp subnet(s) 1326. The app subnet(s) 1326 contained in the data planemirror app tier 1340 can include a virtual network interface controller(VNIC) 1342 (e.g. the VNIC of 1242) that can execute a compute instance1344 (e.g. similar to the compute instance 1244 of FIG. 12 ). Thecompute instance 1344 can facilitate communication between the appsubnet(s) 1326 of the data plane mirror app tier 1340 and the appsubnet(s) 1326 that can be contained in a data plane app tier 1346 (e.g.the data plane app tier 1246 of FIG. 12 ) via the VNIC 1342 contained inthe data plane mirror app tier 1340 and the VNIC 1342 contained in thedata plane app tier 1346.

The Internet gateway 1334 contained in the control plane VCN 1316 can becommunicatively coupled to a metadata management service 1352 (e.g. themetadata management service 1252 of FIG. 12 ) that can becommunicatively coupled to public Internet 1354 (e.g. public Internet1254 of FIG. 12 ). Public Internet 1354 can be communicatively coupledto the NAT gateway 1338 contained in the control plane VCN 1316. Theservice gateway 1336 contained in the control plane VCN 1316 can becommunicatively couple to cloud services 1356 (e.g. cloud services 1256of FIG. 12 ).

In some examples, the data plane VCN 1318 can be contained in thecustomer tenancy 1321. In this case, the IaaS provider may provide thecontrol plane VCN 1316 for each customer, and the IaaS provider may, foreach customer, set up a unique compute instance 1344 that is containedin the service tenancy 1319. Each compute instance 1344 may allowcommunication between the control plane VCN 1316, contained in theservice tenancy 1319, and the data plane VCN 1318 that is contained inthe customer tenancy 1321. The compute instance 1344 may allowresources, which are provisioned in the control plane VCN 1316 that iscontained in the service tenancy 1319, to be deployed or otherwise usedin the data plane VCN 1318 that is contained in the customer tenancy1321.

In other examples, the customer of the IaaS provider may have databasesthat live in the customer tenancy 1321. In this example, the controlplane VCN 1316 can include the data plane mirror app tier 1340 that caninclude app subnet(s) 1326. The data plane mirror app tier 1340 canreside in the data plane VCN 1318, but the data plane mirror app tier1340 may not live in the data plane VCN 1318. That is, the data planemirror app tier 1340 may have access to the customer tenancy 1321, butthe data plane mirror app tier 1340 may not exist in the data plane VCN1318 or be owned or operated by the customer of the IaaS provider. Thedata plane mirror app tier 1340 may be configured to make calls to thedata plane VCN 1318 but may not be configured to make calls to anyentity contained in the control plane VCN 1316. The customer may desireto deploy or otherwise use resources in the data plane VCN 1318 that areprovisioned in the control plane VCN 1316, and the data plane mirror apptier 1340 can facilitate the desired deployment, or other usage ofresources, of the customer.

In some embodiments, the customer of the IaaS provider can apply filtersto the data plane VCN 1318. In this embodiment, the customer candetermine what the data plane VCN 1318 can access, and the customer mayrestrict access to public Internet 1354 from the data plane VCN 1318.The IaaS provider may not be able to apply filters or otherwise controlaccess of the data plane VCN 1318 to any outside networks or databases.Applying filters and controls by the customer onto the data plane VCN1318, contained in the customer tenancy 1321, can help isolate the dataplane VCN 1318 from other customers and from public Internet 1354.

In some embodiments, cloud services 1356 can be called by the servicegateway 1336 to access services that may not exist on public Internet1354, on the control plane VCN 1316, or on the data plane VCN 1318. Theconnection between cloud services 1356 and the control plane VCN 1316 orthe data plane VCN 1318 may not be live or continuous. Cloud services1356 may exist on a different network owned or operated by the IaaSprovider. Cloud services 1356 may be configured to receive calls fromthe service gateway 1336 and may be configured to not receive calls frompublic Internet 1354. Some cloud services 1356 may be isolated fromother cloud services 1356, and the control plane VCN 1316 may beisolated from cloud services 1356 that may not be in the same region asthe control plane VCN 1316. For example, the control plane VCN 1316 maybe located in “Region 1,” and cloud service “Deployment 12,” may belocated in Region 1 and in “Region 2.” If a call to Deployment 12 ismade by the service gateway 1336 contained in the control plane VCN 1316located in Region 1, the call may be transmitted to Deployment 12 inRegion 1. In this example, the control plane VCN 1316, or Deployment 12in Region 1, may not be communicatively coupled to, or otherwise incommunication with, Deployment 12 in Region 2.

FIG. 14 is a block diagram 1400 illustrating another example pattern ofan IaaS architecture, according to at least one embodiment. Serviceoperators 1402 (e.g. service operators 1202 of FIG. 12 ) can becommunicatively coupled to a secure host tenancy 1404 (e.g. the securehost tenancy 1204 of FIG. 12 ) that can include a virtual cloud network(VCN) 1406 (e.g. the VCN 1206 of FIG. 12 ) and a secure host subnet 1408(e.g. the secure host subnet 1208 of FIG. 12 ). The VCN 1406 can includean LPG 1410 (e.g. the LPG 1210 of FIG. 12 ) that can be communicativelycoupled to an SSH VCN 1412 (e.g. the SSH VCN 1212 of FIG. 12 ) via anLPG 1410 contained in the SSH VCN 1412. The SSH VCN 1412 can include anSSH subnet 1414 (e.g. the SSH subnet 1214 of FIG. 12 ), and the SSH VCN1412 can be communicatively coupled to a control plane VCN 1416 (e.g.the control plane VCN 1216 of FIG. 12 ) via an LPG 1410 contained in thecontrol plane VCN 1416 and to a data plane VCN 1418 (e.g. the data plane1218 of FIG. 12 ) via an LPG 1410 contained in the data plane VCN 1418.The control plane VCN 1416 and the data plane VCN 1418 can be containedin a service tenancy 1419 (e.g. the service tenancy 1219 of FIG. 12 ).

The control plane VCN 1416 can include a control plane DMZ tier 1420(e.g. the control plane DMZ tier 1220 of FIG. 12 ) that can include loadbalancer (LB) subnet(s) 1422 (e.g. LB subnet(s) 1222 of FIG. 12 ), acontrol plane app tier 1424 (e.g. the control plane app tier 1224 ofFIG. 12 ) that can include app subnet(s) 1426 (e.g. similar to appsubnet(s) 1226 of FIG. 12 ), a control plane data tier 1428 (e.g. thecontrol plane data tier 1228 of FIG. 12 ) that can include DB subnet(s)1430. The LB subnet(s) 1422 contained in the control plane DMZ tier 1420can be communicatively coupled to the app subnet(s) 1426 contained inthe control plane app tier 1424 and to an Internet gateway 1434 (e.g.the Internet gateway 1234 of FIG. 12 ) that can be contained in thecontrol plane VCN 1416, and the app subnet(s) 1426 can becommunicatively coupled to the DB subnet(s) 1430 contained in thecontrol plane data tier 1428 and to a service gateway 1436 (e.g. theservice gateway of FIG. 12 ) and a network address translation (NAT)gateway 1438 (e.g. the NAT gateway 1238 of FIG. 12 ). The control planeVCN 1416 can include the service gateway 1436 and the NAT gateway 1438.

The data plane VCN 1418 can include a data plane app tier 1446 (e.g. thedata plane app tier 1246 of FIG. 12 ), a data plane DMZ tier 1448 (e.g.the data plane DMZ tier 1248 of FIG. 12 ), and a data plane data tier1450 (e.g. the data plane data tier 1250 of FIG. 12 ). The data planeDMZ tier 1448 can include LB subnet(s) 1422 that can be communicativelycoupled to trusted app subnet(s) 1460 and untrusted app subnet(s) 1462of the data plane app tier 1446 and the Internet gateway 1434 containedin the data plane VCN 1418. The trusted app subnet(s) 1460 can becommunicatively coupled to the service gateway 1436 contained in thedata plane VCN 1418, the NAT gateway 1438 contained in the data planeVCN 1418, and DB subnet(s) 1430 contained in the data plane data tier1450. The untrusted app subnet(s) 1462 can be communicatively coupled tothe service gateway 1436 contained in the data plane VCN 1418 and DBsubnet(s) 1430 contained in the data plane data tier 1450. The dataplane data tier 1450 can include DB subnet(s) 1430 that can becommunicatively coupled to the service gateway 1436 contained in thedata plane VCN 1418.

The untrusted app subnet(s) 1462 can include one or more primary VNICs1464(1)-(N) that can be communicatively coupled to tenant virtualmachines (VMs) 1466(1)-(N). Each tenant VM 1466(1)-(N) can becommunicatively coupled to a respective app subnet 1467(1)-(N) that canbe contained in respective container egress VCNs 1468(1)-(N) that can becontained in respective customer tenancies 1470(1)-(N). Respectivesecondary VNICs 1472(1)-(N) can facilitate communication between theuntrusted app subnet(s) 1462 contained in the data plane VCN 1418 andthe app subnet contained in the container egress VCNs 1468(1)-(N). Eachcontainer egress VCNs 1468(1)-(N) can include a NAT gateway 1438 thatcan be communicatively coupled to public Internet 1454 (e.g. publicInternet 1254 of FIG. 12 ).

The Internet gateway 1434 contained in the control plane VCN 1416 andcontained in the data plane VCN 1418 can be communicatively coupled to ametadata management service 1452 (e.g. the metadata management system1252 of FIG. 12 ) that can be communicatively coupled to public Internet1454. Public Internet 1454 can be communicatively coupled to the NATgateway 1438 contained in the control plane VCN 1416 and contained inthe data plane VCN 1418. The service gateway 1436 contained in thecontrol plane VCN 1416 and contained in the data plane VCN 1418 can becommunicatively couple to cloud services 1456.

In some embodiments, the data plane VCN 1418 can be integrated withcustomer tenancies 1470. This integration can be useful or desirable forcustomers of the IaaS provider in some cases such as a case that maydesire support when executing code. The customer may provide code to runthat may be destructive, may communicate with other customer resources,or may otherwise cause undesirable effects. In response to this, theIaaS provider may determine whether to run code given to the IaaSprovider by the customer.

In some examples, the customer of the IaaS provider may grant temporarynetwork access to the IaaS provider and request a function to beattached to the data plane tier app 1446. Code to run the function maybe executed in the VMs 1466(1)-(N), and the code may not be configuredto run anywhere else on the data plane VCN 1418. Each VM 1466(1)-(N) maybe connected to one customer tenancy 1470. Respective containers1471(1)-(N) contained in the VMs 1466(1)-(N) may be configured to runthe code. In this case, there can be a dual isolation (e.g., thecontainers 1471(1)-(N) running code, where the containers 1471(1)-(N)may be contained in at least the VM 1466(1)-(N) that are contained inthe untrusted app subnet(s) 1462), which may help prevent incorrect orotherwise undesirable code from damaging the network of the IaaSprovider or from damaging a network of a different customer. Thecontainers 1471(1)-(N) may be communicatively coupled to the customertenancy 1470 and may be configured to transmit or receive data from thecustomer tenancy 1470. The containers 1471(1)-(N) may not be configuredto transmit or receive data from any other entity in the data plane VCN1418. Upon completion of running the code, the IaaS provider may kill orotherwise dispose of the containers 1471(1)-(N).

In some embodiments, the trusted app subnet(s) 1460 may run code thatmay be owned or operated by the IaaS provider. In this embodiment, thetrusted app subnet(s) 1460 may be communicatively coupled to the DBsubnet(s) 1430 and be configured to execute CRUD operations in the DBsubnet(s) 1430. The untrusted app subnet(s) 1462 may be communicativelycoupled to the DB subnet(s) 1430, but in this embodiment, the untrustedapp subnet(s) may be configured to execute read operations in the DBsubnet(s) 1430. The containers 1471(1)-(N) that can be contained in theVM 1466(1)-(N) of each customer and that may run code from the customermay not be communicatively coupled with the DB subnet(s) 1430.

In other embodiments, the control plane VCN 1416 and the data plane VCN1418 may not be directly communicatively coupled. In this embodiment,there may be no direct communication between the control plane VCN 1416and the data plane VCN 1418. However, communication can occur indirectlythrough at least one method. An LPG 1410 may be established by the IaaSprovider that can facilitate communication between the control plane VCN1416 and the data plane VCN 1418. In another example, the control planeVCN 1416 or the data plane VCN 1418 can make a call to cloud services1456 via the service gateway 1436. For example, a call to cloud services1456 from the control plane VCN 1416 can include a request for a servicethat can communicate with the data plane VCN 1418.

FIG. 15 is a block diagram 1500 illustrating another example pattern ofan IaaS architecture, according to at least one embodiment. Serviceoperators 1502 (e.g. service operators 1202 of FIG. 12 ) can becommunicatively coupled to a secure host tenancy 1504 (e.g. the securehost tenancy 1204 of FIG. 12 ) that can include a virtual cloud network(VCN) 1506 (e.g. the VCN 1206 of FIG. 12 ) and a secure host subnet 1508(e.g. the secure host subnet 1208 of FIG. 12 ). The VCN 1506 can includean LPG 1510 (e.g. the LPG 1210 of FIG. 12 ) that can be communicativelycoupled to an SSH VCN 1512 (e.g. the SSH VCN 1212 of FIG. 12 ) via anLPG 1510 contained in the SSH VCN 1512. The SSH VCN 1512 can include anSSH subnet 1514 (e.g. the SSH subnet 1214 of FIG. 12 ), and the SSH VCN1512 can be communicatively coupled to a control plane VCN 1516 (e.g.the control plane VCN 1216 of FIG. 12 ) via an LPG 1510 contained in thecontrol plane VCN 1516 and to a data plane VCN 1518 (e.g. the data plane1218 of FIG. 12 ) via an LPG 1510 contained in the data plane VCN 1518.The control plane VCN 1516 and the data plane VCN 1518 can be containedin a service tenancy 1519 (e.g. the service tenancy 1219 of FIG. 12 ).

The control plane VCN 1516 can include a control plane DMZ tier 1520(e.g. the control plane DMZ tier 1220 of FIG. 12 ) that can include LBsubnet(s) 1522 (e.g. LB subnet(s) 1222 of FIG. 12 ), a control plane apptier 1524 (e.g. the control plane app tier 1224 of FIG. 12 ) that caninclude app subnet(s) 1526 (e.g. app subnet(s) 1226 of FIG. 12 ), acontrol plane data tier 1528 (e.g. the control plane data tier 1228 ofFIG. 12 ) that can include DB subnet(s) 1530 (e.g. DB subnet(s) 1430 ofFIG. 14 ). The LB subnet(s) 1522 contained in the control plane DMZ tier1520 can be communicatively coupled to the app subnet(s) 1526 containedin the control plane app tier 1524 and to an Internet gateway 1534 (e.g.the Internet gateway 1234 of FIG. 12 ) that can be contained in thecontrol plane VCN 1516, and the app subnet(s) 1526 can becommunicatively coupled to the DB subnet(s) 1530 contained in thecontrol plane data tier 1528 and to a service gateway 1536 (e.g. theservice gateway of FIG. 12 ) and a network address translation (NAT)gateway 1538 (e.g. the NAT gateway 1238 of FIG. 12 ). The control planeVCN 1516 can include the service gateway 1536 and the NAT gateway 1538.

The data plane VCN 1518 can include a data plane app tier 1546 (e.g. thedata plane app tier 1246 of FIG. 12 ), a data plane DMZ tier 1548 (e.g.the data plane DMZ tier 1248 of FIG. 12 ), and a data plane data tier1550 (e.g. the data plane data tier 1250 of FIG. 12 ). The data planeDMZ tier 1548 can include LB subnet(s) 1522 that can be communicativelycoupled to trusted app subnet(s) 1560 (e.g. trusted app subnet(s) 1460of FIG. 14 ) and untrusted app subnet(s) 1562 (e.g. untrusted appsubnet(s) 1462 of FIG. 14 ) of the data plane app tier 1546 and theInternet gateway 1534 contained in the data plane VCN 1518. The trustedapp subnet(s) 1560 can be communicatively coupled to the service gateway1536 contained in the data plane VCN 1518, the NAT gateway 1538contained in the data plane VCN 1518, and DB subnet(s) 1530 contained inthe data plane data tier 1550. The untrusted app subnet(s) 1562 can becommunicatively coupled to the service gateway 1536 contained in thedata plane VCN 1518 and DB subnet(s) 1530 contained in the data planedata tier 1550. The data plane data tier 1550 can include DB subnet(s)1530 that can be communicatively coupled to the service gateway 1536contained in the data plane VCN 1518.

The untrusted app subnet(s) 1562 can include primary VNICs 1564(1)-(N)that can be communicatively coupled to tenant virtual machines (VMs)1566(1)-(N) residing within the untrusted app subnet(s) 1562. Eachtenant VM 1566(1)-(N) can run code in a respective container1567(1)-(N), and be communicatively coupled to an app subnet 1526 thatcan be contained in a data plane app tier 1546 that can be contained ina container egress VCN 1568. Respective secondary VNICs 1572(1)-(N) canfacilitate communication between the untrusted app subnet(s) 1562contained in the data plane VCN 1518 and the app subnet contained in thecontainer egress VCN 1568. The container egress VCN can include a NATgateway 1538 that can be communicatively coupled to public Internet 1554(e.g. public Internet 1254 of FIG. 12 ).

The Internet gateway 1534 contained in the control plane VCN 1516 andcontained in the data plane VCN 1518 can be communicatively coupled to ametadata management service 1552 (e.g. the metadata management system1252 of FIG. 12 ) that can be communicatively coupled to public Internet1554. Public Internet 1554 can be communicatively coupled to the NATgateway 1538 contained in the control plane VCN 1516 and contained inthe data plane VCN 1518. The service gateway 1536 contained in thecontrol plane VCN 1516 and contained in the data plane VCN 1518 can becommunicatively couple to cloud services 1556.

In some examples, the pattern illustrated by the architecture of blockdiagram 1500 of FIG. 15 may be considered an exception to the patternillustrated by the architecture of block diagram 1400 of FIG. 14 and maybe desirable for a customer of the IaaS provider if the IaaS providercannot directly communicate with the customer (e.g., a disconnectedregion). The respective containers 1567(1)-(N) that are contained in theVMs 1566(1)-(N) for each customer can be accessed in real-time by thecustomer. The containers 1567(1)-(N) may be configured to make calls torespective secondary VNICs 1572(1)-(N) contained in app subnet(s) 1526of the data plane app tier 1546 that can be contained in the containeregress VCN 1568. The secondary VNICs 1572(1)-(N) can transmit the callsto the NAT gateway 1538 that may transmit the calls to public Internet1554. In this example, the containers 1567(1)-(N) that can be accessedin real-time by the customer can be isolated from the control plane VCN1516 and can be isolated from other entities contained in the data planeVCN 1518. The containers 1567(1)-(N) may also be isolated from resourcesfrom other customers.

In other examples, the customer can use the containers 1567(1)-(N) tocall cloud services 1556. In this example, the customer may run code inthe containers 1567(1)-(N) that requests a service from cloud services1556. The containers 1567(1)-(N) can transmit this request to thesecondary VNICs 1572(1)-(N) that can transmit the request to the NATgateway that can transmit the request to public Internet 1554. PublicInternet 1554 can transmit the request to LB subnet(s) 1522 contained inthe control plane VCN 1516 via the Internet gateway 1534. In response todetermining the request is valid, the LB subnet(s) can transmit therequest to app subnet(s) 1526 that can transmit the request to cloudservices 1556 via the service gateway 1536.

It should be appreciated that IaaS architectures 1200, 1300, 1400, 1500depicted in the figures may have other components than those depicted.Further, the embodiments shown in the figures are only some examples ofa cloud infrastructure system that may incorporate an embodiment of thedisclosure. In some other embodiments, the IaaS systems may have more orfewer components than shown in the figures, may combine two or morecomponents, or may have a different configuration or arrangement ofcomponents.

In certain embodiments, the IaaS systems described herein may include asuite of applications, middleware, and database service offerings thatare delivered to a customer in a self-service, subscription-based,elastically scalable, reliable, highly available, and secure manner. Anexample of such an IaaS system is the Oracle Cloud Infrastructure (OCI)provided by the present assignee.

FIG. 16 illustrates an example computer system 1600, in which variousembodiments may be implemented. The system 1600 may be used to implementany of the computer systems described above. As shown in the figure,computer system 1600 includes a processing unit 1604 that communicateswith a number of peripheral subsystems via a bus subsystem 1602. Theseperipheral subsystems may include a processing acceleration unit 1606,an I/O subsystem 1608, a storage sub system 1618 and a communicationssub system 1624. Storage sub system 1618 includes tangiblecomputer-readable storage media 1622 and a system memory 1610.

Bus subsystem 1602 provides a mechanism for letting the variouscomponents and subsystems of computer system 1600 communicate with eachother as intended. Although bus subsystem 1602 is shown schematically asa single bus, alternative embodiments of the bus subsystem may utilizemultiple buses. Bus subsystem 1602 may be any of several types of busstructures including a memory bus or memory controller, a peripheralbus, and a local bus using any of a variety of bus architectures. Forexample, such architectures may include an Industry StandardArchitecture (ISA) bus, Micro Channel Architecture (MCA) bus, EnhancedISA (EISA) bus, Video Electronics Standards Association (VESA) localbus, and Peripheral Component Interconnect (PCI) bus, which can beimplemented as a Mezzanine bus manufactured to the IEEE P1386.1standard.

Processing unit 1604, which can be implemented as one or more integratedcircuits (e.g., a conventional microprocessor or microcontroller),controls the operation of computer system 1600. One or more processorsmay be included in processing unit 1604. These processors may includesingle core or multicore processors. In certain embodiments, processingunit 1604 may be implemented as one or more independent processing units1632 and/or 1634 with single or multicore processors included in eachprocessing unit. In other embodiments, processing unit 1604 may also beimplemented as a quad-core processing unit formed by integrating twodual-core processors into a single chip.

In various embodiments, processing unit 1604 can execute a variety ofprograms in response to program code and can maintain multipleconcurrently executing programs or processes. At any given time, some orall of the program code to be executed can be resident in processor(s)1604 and/or in storage subsystem 1618. Through suitable programming,processor(s) 1604 can provide various functionalities described above.Computer system 1600 may additionally include a processing accelerationunit 1606, which can include a digital signal processor (DSP), aspecial-purpose processor, and/or the like.

I/O subsystem 1608 may include user interface input devices and userinterface output devices. User interface input devices may include akeyboard, pointing devices such as a mouse or trackball, a touchpad ortouch screen incorporated into a display, a scroll wheel, a click wheel,a dial, a button, a switch, a keypad, audio input devices with voicecommand recognition systems, microphones, and other types of inputdevices. User interface input devices may include, for example, motionsensing and/or gesture recognition devices such as the Microsoft Kinect®motion sensor that enables users to control and interact with an inputdevice, such as the Microsoft Xbox® 360 game controller, through anatural user interface using gestures and spoken commands. Userinterface input devices may also include eye gesture recognition devicessuch as the Google Glass® blink detector that detects eye activity(e.g., ‘blinking’ while taking pictures and/or making a menu selection)from users and transforms the eye gestures as input into an input device(e.g., Google Glass®). Additionally, user interface input devices mayinclude voice recognition sensing devices that enable users to interactwith voice recognition systems (e.g., Siri® navigator), through voicecommands.

User interface input devices may also include, without limitation, threedimensional (3D) mice, joysticks or pointing sticks, gamepads andgraphic tablets, and audio/visual devices such as speakers, digitalcameras, digital camcorders, portable media players, webcams, imagescanners, fingerprint scanners, barcode reader 3D scanners, 3D printers,laser rangefinders, and eye gaze tracking devices. Additionally, userinterface input devices may include, for example, medical imaging inputdevices such as computed tomography, magnetic resonance imaging,position emission tomography, medical ultrasonography devices. Userinterface input devices may also include, for example, audio inputdevices such as MIDI keyboards, digital musical instruments and thelike.

User interface output devices may include a display subsystem, indicatorlights, or non-visual displays such as audio output devices, etc. Thedisplay subsystem may be a cathode ray tube (CRT), a flat-panel device,such as that using a liquid crystal display (LCD) or plasma display, aprojection device, a touch screen, and the like. In general, use of theterm “output device” is intended to include all possible types ofdevices and mechanisms for outputting information from computer system1600 to a user or other computer. For example, user interface outputdevices may include, without limitation, a variety of display devicesthat visually convey text, graphics and audio/video information such asmonitors, printers, speakers, headphones, automotive navigation systems,plotters, voice output devices, and modems.

Computer system 1600 may comprise a storage subsystem 1618 thatcomprises software elements, shown as being currently located within asystem memory 1610. System memory 1610 may store program instructionsthat are loadable and executable on processing unit 1604, as well asdata generated during the execution of these programs.

Depending on the configuration and type of computer system 1600, systemmemory 1610 may be volatile (such as random access memory (RAM)) and/ornon-volatile (such as read-only memory (ROM), flash memory, etc.) TheRAM typically contains data and/or program modules that are immediatelyaccessible to and/or presently being operated and executed by processingunit 1604. In some implementations, system memory 1610 may includemultiple different types of memory, such as static random access memory(SRAM) or dynamic random access memory (DRAM). In some implementations,a basic input/output system (BIOS), containing the basic routines thathelp to transfer information between elements within computer system1600, such as during start-up, may typically be stored in the ROM. Byway of example, and not limitation, system memory 1610 also illustratesapplication programs 1612, which may include client applications, Webbrowsers, mid-tier applications, relational database management systems(RDBMS), etc., program data 1614, and an operating system 1616. By wayof example, operating system 1616 may include various versions ofMicrosoft Windows®, Apple Macintosh®, and/or Linux operating systems, avariety of commercially-available UNIX® or UNIX-like operating systems(including without limitation the variety of GNU/Linux operatingsystems, the Google Chrome® OS, and the like) and/or mobile operatingsystems such as iOS, Windows® Phone, Android® OS, BlackBerry® 16 OS, andPalm® OS operating systems.

Storage subsystem 1618 may also provide a tangible computer-readablestorage medium for storing the basic programming and data constructsthat provide the functionality of some embodiments. Software (programs,code modules, instructions) that when executed by a processor providethe functionality described above may be stored in storage subsystem1618. These software modules or instructions may be executed byprocessing unit 1604. Storage subsystem 1618 may also provide arepository for storing data used in accordance with the presentdisclosure.

Storage subsystem 1600 may also include a computer-readable storagemedia reader 1620 that can further be connected to computer-readablestorage media 1622. Together and, optionally, in combination with systemmemory 1610, computer-readable storage media 1622 may comprehensivelyrepresent remote, local, fixed, and/or removable storage devices plusstorage media for temporarily and/or more permanently containing,storing, transmitting, and retrieving computer-readable information.

Computer-readable storage media 1622 containing code, or portions ofcode, can also include any appropriate media known or used in the art,including storage media and communication media, such as but not limitedto, volatile and non-volatile, removable and non-removable mediaimplemented in any method or technology for storage and/or transmissionof information. This can include tangible computer-readable storagemedia such as RAM, ROM, electronically erasable programmable ROM(EEPROM), flash memory or other memory technology, CD-ROM, digitalversatile disk (DVD), or other optical storage, magnetic cassettes,magnetic tape, magnetic disk storage or other magnetic storage devices,or other tangible computer readable media. This can also includenontangible computer-readable media, such as data signals, datatransmissions, or any other medium which can be used to transmit thedesired information and which can be accessed by computing system 1600.

By way of example, computer-readable storage media 1622 may include ahard disk drive that reads from or writes to non-removable, nonvolatilemagnetic media, a magnetic disk drive that reads from or writes to aremovable, nonvolatile magnetic disk, and an optical disk drive thatreads from or writes to a removable, nonvolatile optical disk such as aCD ROM, DVD, and Blu-Ray® disk, or other optical media.Computer-readable storage media 1622 may include, but is not limited to,Zip® drives, flash memory cards, universal serial bus (USB) flashdrives, secure digital (SD) cards, DVD disks, digital video tape, andthe like. Computer-readable storage media 1622 may also include,solid-state drives (SSD) based on non-volatile memory such asflash-memory based SSDs, enterprise flash drives, solid state ROM, andthe like, SSDs based on volatile memory such as solid state RAM, dynamicRAM, static RAM, DRAM-based SSDs, magnetoresistive RAM (MRAM) SSDs, andhybrid SSDs that use a combination of DRAM and flash memory based SSDs.The disk drives and their associated computer-readable media may providenon-volatile storage of computer-readable instructions, data structures,program modules, and other data for computer system 1600.

Communications subsystem 1624 provides an interface to other computersystems and networks. Communications subsystem 1624 serves as aninterface for receiving data from and transmitting data to other systemsfrom computer system 1600. For example, communications subsystem 1624may enable computer system 1600 to connect to one or more devices viathe Internet. In some embodiments communications subsystem 1624 caninclude radio frequency (RF) transceiver components for accessingwireless voice and/or data networks (e.g., using cellular telephonetechnology, advanced data network technology, such as 3G, 4G or EDGE(enhanced data rates for global evolution), WiFi (IEEE 802.11 familystandards, or other mobile communication technologies, or anycombination thereof), global positioning system (GPS) receivercomponents, and/or other components. In some embodiments communicationssubsystem 1624 can provide wired network connectivity (e.g., Ethernet)in addition to or instead of a wireless interface.

In some embodiments, communications subsystem 1624 may also receiveinput communication in the form of structured and/or unstructured datafeeds 1626, event streams 1628, event updates 1630, and the like onbehalf of one or more users who may use computer system 1600.

By way of example, communications subsystem 1624 may be configured toreceive data feeds 1626 in real-time from users of social networksand/or other communication services such as Twitter® feeds, Facebook®updates, web feeds such as Rich Site Summary (RSS) feeds, and/orreal-time updates from one or more third party information sources.

Additionally, communications subsystem 1624 may also be configured toreceive data in the form of continuous data streams, which may includeevent streams 1628 of real-time events and/or event updates 1630 thatmay be continuous or unbounded in nature with no explicit end. Examplesof applications that generate continuous data may include, for example,sensor data applications, financial tickers, network performancemeasuring tools (e.g. network monitoring and traffic managementapplications), clickstream analysis tools, automobile trafficmonitoring, and the like.

Communications subsystem 1624 may also be configured to output thestructured and/or unstructured data feeds 1626, event streams 1628,event updates 1630, and the like to one or more databases that may be incommunication with one or more streaming data source computers coupledto computer system 1600.

Computer system 1600 can be one of various types, including a handheldportable device (e.g., an iPhone® cellular phone, an iPad® computingtablet, a PDA), a wearable device (e.g., a Google Glass® head mounteddisplay), a PC, a workstation, a mainframe, a kiosk, a server rack, orany other data processing system.

Due to the ever-changing nature of computers and networks, thedescription of computer system 1600 depicted in the figure is intendedonly as a specific example. Many other configurations having more orfewer components than the system depicted in the figure are possible.For example, customized hardware might also be used and/or particularelements might be implemented in hardware, firmware, software (includingapplets), or a combination. Further, connection to other computingdevices, such as network input/output devices, may be employed. Based onthe disclosure and teachings provided herein, a person of ordinary skillin the art will appreciate other ways and/or methods to implement thevarious embodiments.

Although specific embodiments have been described, variousmodifications, alterations, alternative constructions, and equivalentsare also encompassed within the scope of the disclosure. Embodiments arenot restricted to operation within certain specific data processingenvironments, but are free to operate within a plurality of dataprocessing environments. Additionally, although embodiments have beendescribed using a particular series of transactions and steps, it shouldbe apparent to those skilled in the art that the scope of the presentdisclosure is not limited to the described series of transactions andsteps. Various features and aspects of the above-described embodimentsmay be used individually or jointly.

Further, while embodiments have been described using a particularcombination of hardware and software, it should be recognized that othercombinations of hardware and software are also within the scope of thepresent disclosure. Embodiments may be implemented only in hardware, oronly in software, or using combinations thereof. The various processesdescribed herein can be implemented on the same processor or differentprocessors in any combination. Accordingly, where components or modulesare described as being configured to perform certain operations, suchconfiguration can be accomplished, e.g., by designing electroniccircuits to perform the operation, by programming programmableelectronic circuits (such as microprocessors) to perform the operation,or any combination thereof. Processes can communicate using a variety oftechniques including but not limited to conventional techniques forinter process communication, and different pairs of processes may usedifferent techniques, or the same pair of processes may use differenttechniques at different times.

The specification and drawings are, accordingly, to be regarded in anillustrative rather than a restrictive sense. It will, however, beevident that additions, subtractions, deletions, and other modificationsand changes may be made thereunto without departing from the broaderspirit and scope as set forth in the claims. Thus, although specificdisclosure embodiments have been described, these are not intended to belimiting. Various modifications and equivalents are within the scope ofthe following claims.

The use of the terms “a” and “an” and “the” and similar referents in thecontext of describing the disclosed embodiments (especially in thecontext of the following claims) are to be construed to cover both thesingular and the plural, unless otherwise indicated herein or clearlycontradicted by context. The terms “comprising,” “having,” “including,”and “containing” are to be construed as open-ended terms (i.e., meaning“including, but not limited to,”) unless otherwise noted. The term“connected” is to be construed as partly or wholly contained within,attached to, or joined together, even if there is something intervening.Recitation of ranges of values herein are merely intended to serve as ashorthand method of referring individually to each separate valuefalling within the range, unless otherwise indicated herein and eachseparate value is incorporated into the specification as if it wereindividually recited herein. All methods described herein can beperformed in any suitable order unless otherwise indicated herein orotherwise clearly contradicted by context. The use of any and allexamples, or exemplary language (e.g., “such as”) provided herein, isintended merely to better illuminate embodiments and does not pose alimitation on the scope of the disclosure unless otherwise claimed. Nolanguage in the specification should be construed as indicating anynon-claimed element as essential to the practice of the disclosure.

Disjunctive language such as the phrase “at least one of X, Y, or Z,”unless specifically stated otherwise, is intended to be understoodwithin the context as used in general to present that an item, term,etc., may be either X, Y, or Z, or any combination thereof (e.g., X, Y,and/or Z). Thus, such disjunctive language is not generally intended to,and should not, imply that certain embodiments require at least one ofX, at least one of Y, or at least one of Z to each be present.

Preferred embodiments of this disclosure are described herein, includingthe best mode known for carrying out the disclosure. Variations of thosepreferred embodiments may become apparent to those of ordinary skill inthe art upon reading the foregoing description. Those of ordinary skillshould be able to employ such variations as appropriate and thedisclosure may be practiced otherwise than as specifically describedherein. Accordingly, this disclosure includes all modifications andequivalents of the subject matter recited in the claims appended heretoas permitted by applicable law. Moreover, any combination of theabove-described elements in all possible variations thereof isencompassed by the disclosure unless otherwise indicated herein.

All references, including publications, patent applications, andpatents, cited herein are hereby incorporated by reference to the sameextent as if each reference were individually and specifically indicatedto be incorporated by reference and were set forth in its entiretyherein. In the foregoing specification, aspects of the disclosure aredescribed with reference to specific embodiments thereof, but thoseskilled in the art will recognize that the disclosure is not limitedthereto. Various features and aspects of the above-described disclosuremay be used individually or jointly. Further, embodiments can beutilized in any number of environments and applications beyond thosedescribed herein without departing from the broader spirit and scope ofthe specification. The specification and drawings are, accordingly, tobe regarded as illustrative rather than restrictive.

What is claimed is:
 1. A method comprising: for a packet transmitted bya graphical processing unit (GPU) of a host machine and received by anetwork device, obtaining, by the network device, a flow informationassociated with the packet; computing, by the network device, based onthe flow information, an outgoing port-link of the network device inaccordance with a hashing algorithm, wherein the hashing algorithm isconfigured to hash packets received on a particular incoming port-linkof the network device to be transmitted on a same outgoing port-link ofthe network device; and forwarding, by the network device, the packet onthe outgoing port-link of the network device.
 2. The method of claim 1,wherein the step of forwarding further comprises: verifying, by thenetwork device, a condition associated with the outgoing port-link ofthe network device; and responsive to the condition being satisfied,forwarding the packet on the outgoing port-link of the network device.3. The method of claim 2, wherein the condition corresponds todetermining whether the outgoing port-link of the network device isactive.
 4. The method of claim 2, further comprising: responsive to thecondition being unsatisfied executing, by the network device, an equalcost multi-path algorithm to obtain a new outgoing port-link of thenetwork device based on the flow information; and forwarding, by thenetwork device, the packet on the new outgoing port-link of the networkdevice.
 5. The method of claim 1, wherein the network device is atop-of-rack (TOR) switch.
 6. The method of claim 1, wherein informationrelated to a hash operation performed on packets received by the networkdevice is stored in a forwarding table database.
 7. The method of claim1, wherein for a first packet and a second packet that are received on afirst incoming port-link of the network device, and a third packet and afourth packet that are received on a second incoming port-link of thenetwork device, the network device is configured for: transmitting, bythe network device, the first packet and the second packet on a firstoutgoing port-link of the network device; and sending, by the networkdevice, the third packet and the fourth packet on a second outgoingport-link of the network device, wherein the first incoming port-link ofthe network device is different than the second incoming port-link ofthe network device, and the first outgoing port-link of the networkdevice is different than the second outgoing port-link of the networkdevice.
 8. The method of claim 7, wherein the first packet, the secondpacket, the third packet and the fourth packet belong to a GPU workload.9. The method of claim 7, wherein the first incoming port-link and thesecond incoming port-link of the network device are a first set of linksconnecting the host machine to a top-of-rack (TOR) switch, and the firstoutgoing port-link and the second outgoing port-link of the networkdevice are a second set of links connecting the TOR to a spine switch.10. A network device comprising: a processor; and a memory includinginstructions that, when executed with the processor, cause the networkdevice to, at least: for a packet transmitted by a graphical processingunit (GPU) of a host machine and received by a network device, obtain aflow information associated with the packet; compute based on the flowinformation, an outgoing port-link of the network device in accordancewith a hashing algorithm, wherein the hashing algorithm is configured tohash packets received on a particular incoming port-link of the networkdevice to be transmitted on a same outgoing port-link of the networkdevice; and forward the packet on the outgoing port-link of the networkdevice.
 11. The network device of claim 10, further configured to:verify a condition associated with the outgoing port-link of the networkdevice; and responsive to the condition being satisfied, forward thepacket on the outgoing port-link of the network device.
 12. The networkdevice of claim 11, wherein the condition corresponds to determiningwhether the outgoing port-link of the network device is active.
 13. Thenetwork device of claim 11, further configured to: responsive to thecondition being unsatisfied execute an equal cost multi-path algorithmto obtain a new outgoing port-link of the network device based on theflow information; and forward the packet on the new outgoing port-linkof the network device.
 14. The network device of claim 10, wherein thenetwork device is a top-of-rack (TOR) switch.
 15. The network device ofclaim 10, wherein information related to a hash operation performed onpackets received by the network device is stored in a forwarding tabledatabase.
 16. The network device of claim 10, wherein for a first packetand a second packet that are received on a first incoming port-link ofthe network device, and a third packet and a fourth packet that arereceived on a second incoming port-link of the network device, thenetwork device is configured to: transmit the first packet and thesecond packet on a first outgoing port-link of the network device; andsend the third packet and the fourth packet on a second outgoingport-link of the network device, wherein the first incoming port-link ofthe network device is different than the second incoming port-link ofthe network device, and the first outgoing port-link of the networkdevice is different than the second outgoing port-link of the networkdevice.
 17. The network device of claim 16, wherein the first packet,the second packet, the third packet and the fourth packet belong to aGPU workload.
 18. The network device of claim 16, wherein the firstincoming port-link and the second incoming port-link of the networkdevice are a first set of links connecting the host machine to atop-of-rack (TOR) switch, and the first outgoing port-link and thesecond outgoing port-link of the network device are a second set oflinks connecting the TOR to a spine switch.
 19. A non-transitorycomputer readable medium storing specific computer-executableinstructions that, when executed by a processor, cause a computer systemto perform operations comprising: for a packet transmitted by agraphical processing unit (GPU) of a host machine and received by anetwork device, obtaining, by the network device, a flow informationassociated with the packet; computing, by the network device, based onthe flow information, an outgoing port-link of the network device inaccordance with a hashing algorithm, wherein the hashing algorithm isconfigured to hash packets received on a particular incoming port-linkof the network device to be transmitted on a same outgoing port-link ofthe network device; and forwarding, by the network device, the packet onthe outgoing port-link of the network device.
 20. The non-transitorycomputer readable medium storing specific computer-executableinstructions of claim 19, wherein the step of forwarding furthercomprises: verifying, by the network device, a condition associated withthe outgoing port-link of the network device; and responsive to thecondition being satisfied, forwarding the packet on the outgoingport-link of the network device.